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Fig.88B-PILLARREINFORCEMENT-QUADCAB
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Fig.89FRONTROOFHEADER-QUADCAB
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Fig.90INNERBODYSIDEAPERTURE-QUADCAB
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Fig.91FRONTCROSSMEMBER-SHORTCARGOBOXONLY
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Fig.92LONGCROSSMEMBER-SHORTCARGOBOXONLY
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Fig.93TAPPINGPLATES-SHORTCARGOBOXONLY
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Fig.94STAKEPOCKETREINFORCEMENTS-SHORTCARGOBOXONLY
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Fig.95OUTERBOXSIDEREINFORCEMENTBRACES-SHORTCARGOBOXONLY
Fig.96OUTERWHEELHOUSE-SHORTCARGOBOXONLY
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Fig.97WELDNUT-SHORTCARGOBOXONLY-SHORTCARGOBOXONLY
Fig.98FRONTBOXPANEL-SHORTCARGOBOXONLY
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Fig.99FRONTCROSSMEMBER-SHORTCARGOBOXONLY
Fig.100BOXFLOORPANEL-SHORTCARGOBOXONLY
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Fig.101FRONTCROSSMEMBER-SHORTCARGOBOXONLY
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Fig.102STAKEPOCKETREINFORCEMENT-SHORTCARGOBOXONLY
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Fig.103INNERTAILGATEPILLARPANEL-SHORTCARGOBOXONLY
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Fig.104BOXFLOORSILLCROSSMEMBER-SHORTCARGOBOXONLY
Fig.105INNERTAILGATEPILLAR-SHORTCARGOBOXONLY
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Fig.106BOXSIDEPANEL-SHORTCARGOBOXONLY
Fig.107FRONTBOXPANEL-SHORTCARGOBOXONLY
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Fig.108INNERBOXSIDEPANEL-SHORTCARGOBOXONLY
Fig.109OUTERWHEELHOUSEPANEL-SHORTCARGOBOXONLY
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Fig.110FRONTCROSSMEMBER-LONGCARGOBOXONLY
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Fig.111WHEELHOUSECROSSMEMBER-LONGCARGOBOXONLY
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Fig.112FRONTANDCENTERSTAKEPOCKETREINFORCEMENTS-LONGCARGOBOXONLY
Fig.113OUTERFRONTANDCENTERSTAKEPOCKETREINFORCEMENT-LONGCARGOBOXONLY
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Fig.114OUTERWHEELHOUSE-LONGCARGOBOXONLY
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Fig.115TAILGATEBOXSIDEPIVOTREINFORCEMENT-LONGCARGOBOXONLY
Fig.116FRONTBOXSIDEPANEL-LONGCARGOBOXONLY
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Fig.117FRONTBOXSIDEPANEL-LONGCARGOBOXONLY
Fig.118BOXFRONTPANEL-LONGCARGOBOXONLY
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Fig.119BOXFLOORPANEL-LONGCARGOBOXONLY
Fig.120LONGCROSSMEMBERS-LONGCARGOBOXONLY
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Fig.121INNERWHEELHOUSEPANEL-LONGCARGOBOXONLY
Fig.122TAILGATEPILLAROUTERPANEL-LONGCARGOBOXONLY
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Fig.123REARSILLCROSSBOX-LONGCARGOBOXONLY
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Fig.124OUTERBOXSIDEPANEL-LONGCARGOBOXONLY
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Fig.125STAKEPOCKETREINFORCEMENTS-LONGCARGOBOXONLY
Fig.126TAILGATEPIVOTREINFORCEMENT-LONGCARGOBOXONLY
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Fig.127INNERWHEELHOUSE-LONGCARGOBOXONLY
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Fig.129INNERDOORPANEL-QUADCAB
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Fig.130INNERDOORPANEL-STANDARDCAB
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Fig.131INNERDOORPANEL-QUADCAB
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HEATING & AIR CONDITIONING
24 - 1
HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page
page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 2
CONDITIONER . . . . . . . . . . . . . . . . . . . . . . . . 1
DIAGNOSIS AND TESTING - HEATER
DESCRIPTION - COOLING SYSTEM
PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 5
REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . 1
STANDARD PROCEDURE - DIODE
DESCRIPTION - REFRIGERANT SYSTEM
SERVICE PORT . . . . . . . . . . . . . . . . . . . . . . . . 1
REPLACEMENT SPECIFICATIONS
. . . . . . . . . . . . . . . . . . . . . . . 7
OPERATION
OPERATION - HEATER AND AIR
CONDITIONER . . . . . . . . . . . . . . . . . . . . . . . . 1
OPERATION - REFRIGERANT SYSTEM
SERVICE PORT . . . . . . . . . . . . . . . . . . . . . . . . 2
A/C APPLICATION TABLE . . . . . . . . . . . . . . . . 7
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . 8
CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . . 24
PLUMBING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - HEATER AND AIR CONDITIONER
All vehicles are equipped with a common HVAC housing assembly (Fig. 1). The system combines air conditioning, heating, and ventilating capabilities in a single unit housing mounted under the instrument panel.
DESCRIPTION - COOLING SYSTEM REQUIREMENTS
To maintain the performance level of the HVAC system, the engine cooling system must be properly maintained. The use of a bug screen is not recom- mended. Any obstructions in front of the radiator or condenser will reduce the performance of the air con- ditioning and engine cooling systems.
The engine cooling system includes the heater core and the heater hoses. Refer to Engine Cooling for more information before the opening of, or attempt- ing any service to the engine cooling system.
DESCRIPTION - REFRIGERANT SYSTEM SERVICE PORT
The two refrigerant system service ports are used to charge, recover/recycle, evacuate, and test the air conditioning refrigerant system. Unique service port coupler sizes are used on the R-134a system, to
ensure that the refrigerant system is not accidentally contaminated by the use of the wrong refrigerant (R-12), or refrigerant system service equipment.
OPERATION
OPERATION - HEATER AND AIR CONDITIONER The heater air conditioner are blend-air type sys- tems. In a blend-air system, a blend door controls the amount of unconditioned air (or cooled air from the evaporator on models with air conditioning) that is allowed to flow through, or around, the heater core. A temperature control knob on the A/C Heater control panel determines the discharge air temperature by controlling an electric actuator, which moves the blend door. This allows an almost immediate control of the output air temperature of the system.
The mode control knob on the A/C Heater control panel is used to direct the conditioned air to the selected system outlets. Both mode control switches use electric actuators to control the mode doors.
On all vehicles, the outside air intake can be shut off by selecting the Recirculation Mode with the mode control knob. This will operate a electric actu- ated recirculation door that closes off the outside fresh air intake and recirculates the air that is already inside the vehicle.
The air conditioner for all models is designed for the use of non-CFC, R-134a refrigerant. The air con- ditioning system has an evaporator to cool and dehu- midify the incoming air prior to blending it with the heated air. This air conditioning system uses a fixed orifice tube in the liquid line near the condenser out- let tube to meter refrigerant flow to the evaporator
HEATING & AIR CONDITIONING
24 - 2
HEATING & AIR CONDITIONING (Continued)DR
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C PERFORMANCE
The air conditioning system is designed to provide the passenger compartment with low temperature and low humidity air. The evaporator, located in the HVAC housing on the dash panel below the instru- ment panel, is cooled to temperatures near the freez- ing point. As warm damp air passes through the cooled evaporator, the air transfers its heat to the refrigerant in the evaporator and the moisture in the air condenses on the evaporator fins. During periods of high heat and humidity, an air conditioning sys- tem will be more effective in the Recirculation Mode. With the system in the Recirculation Mode, only air from the passenger compartment passes through the evaporator. As the passenger compartment air dehu- midifies, the air conditioning system performance levels improve.
Humidity has an important bearing on the temper- ature of the air delivered to the interior of the vehi- cle. It is important to understand the effect that humidity has on the performance of the air condition- ing system. When humidity is high, the evaporator has to perform a double duty. It must lower the air temperature, and it must lower the temperature of the moisture in the air that condenses on the evapo- rator fins. Condensing the moisture in the air trans- fers heat energy into the evaporator fins and tubing. This reduces the amount of heat the evaporator can absorb from the air. High humidity greatly reduces the ability of the evaporator to lower the temperature of the air.
However, evaporator capacity used to reduce the amount of moisture in the air is not wasted. Remov- ing some of the moisture out of the air entering the vehicle adds to the comfort of the passengers. Although, an owner may expect too much from the air conditioning system on humid days. A perfor- mance test is the best way to determine whether the system is performing up to standard. This test also provides valuable clues as to the possible cause of trouble with the air conditioning system.
Before proceeding, (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNING) and (Refer to 24 - HEATING & AIR CONDITIONING/ PLUMBING - CAUTION). The air temperature in the test room and in the vehicle must be a minimum of 21° C (70° F) for this test.
(1) Connect a tachometer and a manifold gauge set
or A/C recycling/charging station.
(2) Set the A/C Heater mode control switch knob in the Recirculation Mode position, the temperature control knob in the full cool position, and the blower motor switch knob in the highest speed position.
Fig.1HVACHousing-DualZoneShown(Typical-
SingleZone)
1 - Mounting Nut 2 - Passenger Blend Door Actuator (dual zone) 3 - Mounting Nut 4 - Air Intake Spacer 5 - Recirculation Door Actuator 6 - Recirculation Door Assembly 7 - Driver Side Blend Door Actuator 8 - HVAC Housing 9 - Mounting Screw 10 - Defroster Door Actuator 11 - Panel Actuator
coil. To maintain minimum evaporator temperature and prevent evaporator freezing, the A/C Fin Probe which is located in the evaporator cycles the com- pressor clutch by sending an A/C request to the JTEC which in turn processes this piece of informa- tion and if all conditions are met cycles the compres- sor clutch.
OPERATION - REFRIGERANT SYSTEM SERVICE PORT
The low pressure service port is located on the suc- tion refrigerant line, near the accumulator. The high pressure service port is located on the liquid line at the passenger side of the engine compartment, near the condenser.
Each of the service ports has a threaded plastic protective cap installed over it from the factory. After servicing the refrigerant system, always reinstall both of the service port caps.
DR HEATING & AIR CONDITIONING (Continued)
HEATING & AIR CONDITIONING
24 - 3
(3) Start the engine and hold the idle at 1,000 rpm
with the compressor clutch engaged.
(4) The engine should be at operating temperature.
The doors and windows must be closed.
(5) Insert a thermometer in the driver side center A/C (panel) outlet. Operate the engine for five min- utes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.
(7) With the compressor clutch engaged, record the discharge air temperature and the compressor dis- charge pressure.
(8) Compare the discharge air temperature to the Performance Temperature and Pressure chart. If the discharge air temperature is high, (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - DIAGNOSIS AND TESTING - REFRIGERANT SYS- TEM LEAKS) and (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - SPECIFICATIONS - CHARGE CAPACITY).
Ambient Air Temperature Air Temperature at Center Panel Outlet Compressor Inlet Pressure at Service Port (low Side)
Condensor Out Pressuree at Service Port (High Side)
Performance Temperature and Pressure
21° C (70° F) 7° C (45° F)
27° C (80° F) 7° C (45° F)
32° C (90° F) 13° C (55° F)
38° C (100° F) 13° C (55° F)
43° C (110° F) 18° C (64° F)
138 to 207 kPa (20 to 30 psi)
1034 to 1724
kPa
172 to 241
207 to 276
241 to 310
kPa
(25 to 35 psi) 1379 to 2068
kPa
kPa
(30 to 40 psi) 1724 to 2413
kPa
kPa
(35 to 45 psi) 1999 to 2689
kPa
(150 to 250
(200 to 300
(250 to 350
(290 to 390
psi)
psi)
psi)
psi)
276 to 345 kPa (40 to 50 psi)
2413 to 2965
kPa
(350 to 430 psi)
(9) Compare the compressor discharge pressure to the Performance Temperature and Pressure chart. If
the compressor discharge pressure is high, see the Pressure Diagnosis chart.
Condition
Possible Causes
Correction
Pressure Diagnosis
Constant compressor
engagement and warm air
from passenger vents.
1. Low refrigerant system
charge.
Equal pressures, but the compressor clutch does not engage.
1. No refrigerant in the refrigerant system.
2. Faulty fuse.
3. Faulty a/c compressor clutch coil.
1. See Plumbing/Diagnosis and Testing - Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required.
1. See Plumbing/Diagnosis and Testing - Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required. 2. Check the fuses in the Power Distribution Center and the junction block. Repair the shorted circuit or component and replace the fuses, if required. 3. See A/C Compressor/Diagnosis and Testing - Compressor Clutch Coil in this group. Test the compressor clutch coil and replace, if required.
HEATING & AIR CONDITIONING
24 - 4
HEATING & AIR CONDITIONING (Continued)DR
Condition
Possible Causes
Correction
Pressure Diagnosis
4. Faulty a/c compressor clutch relay.
5. Improperly installed or faulty Fin Sensor.
6. Faulty a/c high pressure transducer.
7. Faulty Powertrain Control Module (PCM).
1. Excessive refrigerant oil in system.
2. Blend door inoperative or sealing improperly.
3. Blend door actuator faulty or inoperative.
1. Low refrigerant system charge.
2. Refrigerant flow through the accumulator is restricted. 3. Refrigerant flow through the evaporator coil is restricted. 4. Faulty compressor.
Normal pressures, but A/C Performance Test air temperatures at center panel outlet are too high.
The low side pressure is normal or slightly low, and the high side pressure is too low.
The low side pressure is normal or slightly high, and the high side pressure is too high.
1. Condenser air flow restricted.
2. Inoperative cooling fan.
3. Refrigerant system overcharged.
4. See A/C Compressor Clutch Relay/Diagnosis and Testing - Compressor Clutch Relay in this group. Test the compressor clutch relay and relay circuits. Repair the circuits or replace the relay, if required. 5. See Fin Sensor/Diagnosis and Testing in this group. Reinstall or replace the Fin Sensor as required. 6. See A/C High Pressure Transducer/Diagnosis and Testing in this group. Test the a/c high pressure transducer and replace, if required. 7. (Refer to Appropriate Diagnostic Information). Test the PCM and replace, if required.
1. See Refrigerant Oil/Standard Procedure - Refrigerant Oil Level in this group. Recover the refrigerant from the refrigerant system and inspect the refrigerant oil content. Restore the refrigerant oil to the proper level, if required. 2. See Blend Door in this group. Inspect the blend door for proper operation and sealing and correct, if required. 3. Perform blend door actuator diagnosis, replace if faulty.
1. See Plumbing/Diagnosis and Testing - Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required. 2. See Accumulator in this group. Replace the restricted accumulator, if required. 3. See A/C Evaporator in this group. Replace the restricted evaporator coil, if required.
4. See A/C Compressor in this group. Replace the compressor, if required.
1. Check the condenser for damaged fins, foreign objects obstructing air flow through the condenser fins, and missing or improperly installed air seals. Refer to Cooling for more information on air seals. Clean, repair, or replace components as required. 2. Refer to Cooling for more information. Test the cooling fan and replace, if required. 3. See Plumbing/Standard Procedure - Refrigerant System Charge in this group. Recover the refrigerant from the refrigerant system. Charge the refrigerant system to the proper level, if required.
DR HEATING & AIR CONDITIONING (Continued)
HEATING & AIR CONDITIONING
24 - 5
Condition
Possible Causes
Correction
Pressure Diagnosis
4. Air in the refrigerant system.
5. Engine overheating.
The low side pressure is too high, and the high side pressure is too low.
1. Accessory drive belt slipping.
2. Fixed orifice tube not installed. 3. Faulty compressor.
The low side pressure is too low, and the high side pressure is too high.
1. Restricted refrigerant flow through the refrigerant lines.
2. Restricted refrigerant flow through the fixed orifice tube. 3. Restricted refrigerant flow through the condenser.
4. See Plumbing/Diagnosis and Testing - Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required. 5. Refer to Cooling for more information. Test the cooling system and repair, if required.
1. Refer to Cooling for more information. Inspect the accessory drive belt condition and tension. Tighten or replace the accessory drive belt, if required. 2. See A/C Orifice Tube in this group. Replace the liquid line, if required. 3. See A/C Compressor in this group. Replace the compressor, if required.
1. See Liquid, Suction, and Discharge Line in this group. Inspect the refrigerant lines for kinks, tight bends or improper routing. Correct the routing or replace the refrigerant line, if required. 2. See A/C Orifice Tube in this group. Replace the liquid line, if required. 3. See A/C Condenser in this group. Replace the restricted condenser, if required.
DIAGNOSIS AND TESTING - HEATER PERFORMANCE
Before performing the following tests, refer to Cool- ing for the procedures to check the engine coolant level and flow, engine coolant reserve/recovery sys- tem operation, accessory drive belt condition and ten- sion, radiator air flow and the fan drive operation. Also be certain that the accessory vacuum supply line is connected at the engine vacuum source.
MAXIMUM HEATER OUTPUT
Engine coolant is delivered to the heater core through two heater hoses. With the engine idling at normal operating temperature, set the temperature control knob in the full hot position, the mode control switch knob in the floor position, and the blower motor switch knob in the highest speed position. Using a test thermometer, check the temperature of the air being discharged at the HVAC housing floor outlets. Compare the test thermometer reading to the Temperature Reference chart.
Ambient Air Temperature
Minimum Air Temperature at Floor Outlet
Temperature Reference 21.1° C (70° F) 63.8° C (147° F)
15.5° C (60° F) 62.2° C (144° F)
26.6° C (80° F) 65.5° C (150° F)
32.2° C (90° F) 67.2° C (153° F)
HEATING & AIR CONDITIONING
24 - 6
HEATING & AIR CONDITIONING (Continued)DR
If the floor outlet air temperature is too low, refer to Cooling to check the engine coolant temperature specifications. Both of the heater hoses should be hot to the touch. The coolant return heater hose should be slightly cooler than the coolant supply heater hose. If the return hose is much cooler than the sup- ply hose, locate and repair the engine coolant flow obstruction in the cooling system. Refer to Cooling for the procedures.
An alternate method of checking heater perfor- mance is to use a DRBIIIt scan tool to monitor the engine coolant temperature. The floor outlet air tem- perature reading should be no more than 4.5° C (40° F) lower than the engine coolant temperature read- ing.
OBSTRUCTED COOLANT FLOW Possible loca- tions or causes of obstructed coolant flow: † Faulty water pump. † Faulty thermostat. † Pinched or kinked heater hoses. † Improper heater hose routing. † Plugged heater hoses or supply and return ports † A plugged heater core.
at the cooling system connections.
If proper coolant flow through the cooling system is verified, and heater outlet air temperature is still low, a mechanical problem may exist.
causes of insufficient heat:
MECHANICAL PROBLEMS Possible locations or † An obstructed cowl air intake. † Obstructed heater system outlets. † A faulty, obstructed or † A faulty blower system. † A faulty a/c heater control.
improperly installed
blend door.
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be adjusted with the temperature control knob on the a/c heater control panel, the following could require service:
† A faulty a/c heater control. † A faulty blend door actuator. † A faulty, obstructed or † An obstructed cowl air intake. † The engine cooling system.
blend door.
improperly installed
CONDITION
POSSIBLE CAUSE
CORRECTION
Heater Diagnosis
INSUFFICIENT HEATER OUTPUT.
1. Incorrect engine coolant level. 2. Air trapped in engine cooling system. 3. Incorrect engine coolant temperature.
4. Blend door actuator inoperative or defective. 5. Blend door not operating properly.
6. Insufficient air flow through heater housing. 7. Improper blower motor operation.
1. Check the engine coolant level. Refer to Cooling for the procedures. 2. Check the operation of the coolant reserve/recovery system. Refer to Cooling for the procedures. 3. Check the performance and operation of the engine cooling system including: thermostat, water pump, fan drive, accessory drive belt, coolant flow (plugged radiator or heater core, plugged or kinked coolant hoses), air flow (missing or improperly installed radiator air seals or fan shroud). Refer to Cooling for the procedures. 4. (Refer to Controls/Blend Door Actuator) in this group.
5. Check for a damaged, obstructed or improperly installed blend door or seals. (Refer to Controls/Blend Door Actuator) in this group. 6. Remove foreign material or obstructions from cowl air intake. 7. (Refer to Distribution/Blower Motor/ Diagnosis and Testing) in this group.
DR HEATING & AIR CONDITIONING (Continued) STANDARD PROCEDURE - DIODE REPLACEMENT
(1) Disconnect the battery negative cable and iso- late it. If vehicle has a dual batterys remove both negative cables.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 2).
Fig.2DIODEIDENTIFICATION
1 - CURRENT FLOW 2 - BAND AROUND DIODE INDICATES CURRENT FLOW 3 - DIODE AS SHOWN IN THE DIAGRAMS
(4) Remove the insulation from the wires in the harness. Only remove enough insulation to solder in the new diode.
(5) Install the new diode in the harness, making sure current flow is correct. If necessary refer to the appropriate wiring diagram for current flow.
(6) Solder the connections together using rosin core type solder only. Do not use acid core solder. (7) Tape the diode to the harness using electrical tape making, sure the diode is completely sealed from the elements.
(8) Re-connect the battery negative cable(s), and
test affected systems.
HEATING & AIR CONDITIONING
24 - 7
SPECIFICATIONS
A/C APPLICATION TABLE
Notes
SP-15 PAG oil Evaporator mounted discharge line
Software - J2190
resistor block
PCM ± 0.5V @ 70° F
Item Vehicle System
Compressor Freeze–up Control High psi Control
Control Head
Mode Door Blend Door Recirculation Door Blower Motor
Cooling Fan
Clutch
Control Draw
Gap DRB IIIT Reads
Actuators
Description DR- Ram Truck R134a w/ fixed orifice tube Saden SD-7
A/C Fin Sensor475 psi A/C cut out electronic
electric electric electric
hardwired to control head Viscous for cooling with a single speed electric for A/C for 3.7, 4.7 and 5.7L gas engines. Viscous for both cooling and A/C with 5.9L diesel engine and 8.0L gas engine. Electro- mechanical relay 2 - 3.7 amps @ 12V 0.0169 - 0.0319
TPS, RPM, A/C switch test clutch and fan relay
HEATING & AIR CONDITIONING
24 - 8
HEATING & AIR CONDITIONING (Continued) SPECIFICATIONSTORQUE SPECIFICATIONS
DR
DESCRIPTION
A/C COMPRESSOR CLUTCH PLATE NUT
A/C COMPRESOR LINE MANIFOLD FASTENER A/C COMPRESSOR TO MOUNTING BRACKET
BOLTS
ACCUMULATOR RETAINING BOLT
N·m
14.4
28 (±6)
27
BLEND DOOR ACTUATOR
2.4 (±.34)
SCREWS
HVAC HOUSING SCREWS HVAC HOUSING TO DASH
PANEL NUTS
SUCTION LINE TO
ACCUMULATOR FITTING
2.4 (±.34)
6.2
Ft. Lbs.
10.5
21 (±4)
20
3.7
1.8 (±.25)
1.8 (±.25)
4.6
6.6
In. Lbs.
127.4
250 (±50)
239
44
21 (±3)
21 (±3)
55
80
DR
CONTROLS
24 - 9
CONTROLS
TABLE OF CONTENTS
page
page
A/C COMPRESSOR CLUTCH
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 9
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
DIAGNOSIS AND TESTING - A/C COMPRESSOR CLUTCH COIL STANDARD PROCEDURE - A/C. . . . . . . . . . . 10
COMPRESSOR CLUTCH BREAK-IN
. . . . . . . 10
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 12
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 12A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 13
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
DIAGNOSIS AND TESTING - COMPRESSORCLUTCH RELAY
. . . . . . . . . . . . . . . . . . . . . . 13
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 14A/C HEATER CONTROL
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 14
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 15A/C PRESSURE TRANSDUCER
DESCRIPTION - A/C PRESSURE
TRANSDUCER
. . . . . . . . . . . . . . . . . . . . . . . 15
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DIAGNOSIS AND TESTING - A/C PRESSURETRANSDUCER
. . . . . . . . . . . . . . . . . . . . . . . 15
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 16BLEND DOOR ACTUATOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 16A/C COMPRESSOR CLUTCH DESCRIPTION
The compressor clutch assembly consists of a sta- tionary electromagnetic coil, a rotor bearing and rotor assembly, and a clutch plate (Fig. 1). The elec- tromagnetic coil unit and the rotor bearing and rotor assembly are each retained on the nose of the com- pressor front housing with snap rings. The clutch plate is keyed to the compressor shaft and secured with a nut. These components provide the means to engage and disengage the compressor from the engine serpentine accessory drive belt.
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 17BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 17
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
DIAGNOSIS AND TESTING - BLOWERMOTOR RESISTOR . . . . . . . . . . . . . . . . . . . . 18
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 18BLOWER MOTOR SWITCH
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 18
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DIAGNOSIS AND TESTING - BLOWERMOTOR SWITCH . . . . . . . . . . . . . . . . . . . . . . 18
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19DEFROST DOOR ACTUATOR
REMOVAL - FLOOR - DEFROST DOOR
ACTUATOR . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION - FLOOR - DEFROST DOOR
ACTUATOR . . . . . . . . . . . . . . . . . . . . . . . . . . 20
MODE DOOR ACTUATOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 20
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 22RECIRCULATION DOOR ACTUATOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 22
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 23OPERATION
When the clutch coil is energized, it magnetically draws the clutch into contact with the rotor and drives the compressor shaft. When the coil is not energized, the rotor freewheels on the clutch rotor bearing, which is part of the rotor. The compressor clutch and coil are the only serviced parts on the compressor.
The compressor clutch engagement is controlled by several components: the A/C Heater mode control switch, the A/C high pressure transducer, the com- pressor clutch relay, and the (JTEC). The JTEC may delay compressor clutch engagement for up to thirty
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A/C COMPRESSOR CLUTCH (Continued)DR
† JTEC (4) The compressor clutch coil is acceptable if the current draw measured at the clutch coil is 2.0 to 3.9
amperes with the electrical system voltage at 11.5 to 12.5 volts. This should only be checked with the work area temperature at 21° C (70° F). If system voltage is more than 12.5 volts, add electrical loads by turn- ing on electrical accessories until the system voltage drops below 12.5 volts.(a) If the clutch coil current reading is four amperes or more, the coil is shorted and should be replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
Fig.1COMPRESSORCLUTCH-TYPICAL
1 - CLUTCH PLATE 2 - SHAFT KEY (not used on KJ) 3 - ROTOR 4 - COIL 5 - CLUTCH SHIMS 6 - SNAP RING 7 - SNAP RING
seconds. Refer to Electronic Control Modules for more information on the JTEC controls.
DIAGNOSIS AND TESTING - A/C COMPRESSOR CLUTCH COIL
For circuit descriptions and diagrams, (Refer to Appropriate Wiring Information). The battery must be fully-charged before performing the following tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in series with the clutch coil terminal. Use a voltmeter (0 to 20 volt scale) with clip-type leads for measuring the voltage across the battery and the compressor clutch coil.
(2) With the A/C Heater mode control switch in any A/C mode, and the blower motor switch in the lowest speed position, start the engine and run it at normal idle.
(3) The compressor clutch coil voltage should read within 0.2 volts of the battery voltage. If there is voltage at the clutch coil, but the reading is not within 0.2 volts of the battery voltage, test the clutch coil feed circuit for excessive voltage drop and repair as required. If there is no voltage reading at the clutch coil, use a DRB III t scan tool and (Refer to Appropriate Diagnostic Information) for testing of the compressor clutch circuit and PCM control. The fol- lowing components must be checked and repaired as required before you can complete testing of the clutch coil:† Fuses in the junction block and the Power Dis- tribution Center (PDC) † A/C heater mode control switch † Compressor clutch relay † A/C high pressure transducer switch
STANDARD PROCEDURE - A/C COMPRESSOR CLUTCH BREAK-IN
After a new compressor clutch has been installed, cycle the compressor clutch approximately twenty times (five seconds on, then five seconds off). During this procedure, set the A/C Heater control to the Recirculation Mode, the blower motor switch in the highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat the opposing friction surfaces and provide a higher compressor clutch torque capability.REMOVAL
The refrigerant system can remain fully-charged during compressor clutch, rotor, or coil replacement. The compressor clutch can be serviced in the vehicle. (1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
(3) Unplug the compressor clutch coil wire harness
connector.
(4) Remove the bolts that secure the compressor to
the mounting bracket.
(5) Remove the compressor from the mounting bracket. Support the compressor in the engine com- partment while servicing the clutch.
(6) Insert the two pins of the spanner wrench (Special Tool C-4489 or equivalent) into the holes of the clutch plate. Hold the clutch plate stationary and remove the hex nut (Fig. 2).
(7) Remove the clutch plate. (8) Remove the compressor clutch shims. (9) Remove the external front housing snap ring
with snap ring pliers (Fig. 3).
(10) Install the lip of the rotor puller (Special Tool C-6141-1 or equivalent) into the snap ring groove exposed in the previous step, and install the shaft pro- tector (Special Tool C-6141-2 or equivalent) (Fig. 4).
DR A/C COMPRESSOR CLUTCH (Continued)
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24 - 11
(11) Install the puller through-bolts (Special Tool C-6461 or equivalent) through the puller flange and into the jaws of the rotor puller and tighten (Fig. 5). Turn the puller center bolt clockwise until the rotor is free.
CAUTION: DO NOT APPLY FORCE TO THE END OF THE COMPRESSOR SHAFT.
Fig.2CLUTCHNUTREMOVE-Typical
1 - CLUTCH PLATE 2 - SPANNER
Fig.3EXTERNALSNAPRINGREMOVE-Typical 1 - PULLEY 2 - SNAP RING PLIERS
Fig.5INSTALLPULLERPLATE-Typical
1 - PULLER JAW 2 - PULLER
(12) Remove the screw and retainer from the clutch coil lead wire harness on the compressor front housing (Fig. 6).
Fig.6CLUTCHCOILLEADWIREHARNESS-
Typical
1 - COIL 2 - COIL WIRE 3 - RETAINER SCREW
Fig.4SHAFTPROTECTORANDPULLER-Typical 1 - PULLER JAW 2 - SHAFT PROTECTOR
(13) Remove the snap ring from the compressor hub and remove the clutch field coil (Fig. 7). Slide the clutch field coil off of the compressor hub.
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24 - 12
A/C COMPRESSOR CLUTCH (Continued)DR
Fig.7CLUTCHFIELDCOILSNAPRINGREMOVE-
Fig.8CLUTCHPULLEYINSTALL-Typical
Typical
1 - ROTOR BEARING ASSEMBLY 2 - INSTALLER
1 - COIL 2 - SNAP RING PLIERS
INSPECTION
Examine the friction surfaces of the clutch rotor and the clutch plate for wear. The rotor and clutch plate should be replaced if there is excessive wear or scoring.
If the friction surfaces are oily, inspect the shaft and nose area of the compressor for oil. Remove the felt from the front cover. If the felt is saturated with oil, the shaft seal is leaking and the compressor must be replaced.
Check the rotor bearing for roughness or excessive leakage of grease. Replace the rotor and clutch plate, if required.
INSTALLATION
(1) Install the clutch field coil and snap ring. (2) Install the screw and retainer on the clutch coil lead wire harness on the compressor front housing. Tighten screw to 2.2 N·m (20 in. lbs.).
(3) Align the rotor assembly squarely on the front
compressor housing hub.
(4) Install the rotor bearing assembly with the installer (Special Tool C-6871 or equivalent) (Fig. 8). Thread the installer on the shaft, then turn the nut until the rotor assembly is seated.
(5) Install the external front housing snap ring with snap ring pliers. The bevel side of the snap ring must be facing outward. Press the snap ring to make sure it is properly seated in the groove.
CAUTION: If the snap ring is not fully seated in the groove it will vibrate out, resulting in a clutch fail- ure and severe damage to the front housing of the compressor.
(6) Install the original clutch shims on the com-
pressor shaft.
(7) Install the clutch plate. Install the shaft hex
nut and tighten to 15–20 N·m (11–15 ft. lbs.).
(8) Check the clutch air gap with a feeler gauge (Fig. 9). If the air gap does not meet the specification, add or subtract shims as required. The air gap spec- ification is 0.41 to 0.79 millimeter (0.016 to 0.031
inch).Fig.9CHECKCLUTCHAIRGAP-Typical
1 - FEELER GAUGE
DR A/C COMPRESSOR CLUTCH (Continued)
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24 - 13
NOTE: The air gap is determined by the spacer shims. When installing an original, or a new clutch assembly, try the original shims first. When install- ing a new clutch onto a compressor that previously did not have a clutch, use a 1.0, 0.50, and 0.13 mil- limeter (0.040, 0.020, and 0.005 inch) shims from the new clutch hardware package that is provided with the new clutch.
(2) Resistance between terminals 85 and 86 (elec- tromagnet) should be 67.5 to 82.5 ohms. If OK, go to Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86. There should now be continuity between terminals 30 and 87, and no continuity between terminals 87A and 30. If OK, see Relay Circuit Test. If not OK, replace the faulty relay.
(9) To complete the procedure,
(Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/A/C COMPRESSOR - INSTALLATION).
A/C COMPRESSOR CLUTCH RELAY DESCRIPTION
ISO relay. However,
The compressor clutch relay is a International Standards Organization (ISO) micro-relay. The termi- nal designations and functions are the same as a con- ventional the micro-relay terminal orientation (footprint) is different, the cur- rent capacity is lower, and the relay case dimensions are smaller than those of the conventional ISO relay. The compressor clutch relay is located in the Power Distribution Center (PDC) in the engine compart- ment. Refer to the PDC label for relay identification and location.
OPERATION
The compressor clutch relay is a electromechanical device that switches battery current to the compres- sor clutch coil when the Powertrain Control Module (PCM) grounds the coil side of the relay. The PCM responds to inputs from the A/C Heater mode control switch, the A/C low pressure switch, and the A/C high pressure switch. (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS/A/C COMPRESSOR CLUTCH RELAY - DIAGNOSIS AND TESTING)
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - COMPRESSOR CLUTCH RELAY
RELAY TEST
The compressor clutch relay (Fig. 10) is located in the Power Distribution Center (PDC). Refer to the PDC label relay identification and location. Remove the relay from the PDC to perform the fol- lowing tests:
for
(1) A relay in the de-energized position should have continuity between terminals 87A and 30, and no continuity between terminals 87 and 30. If OK, go to Step 2. If not OK, replace the faulty relay.
Fig.10COMPRESSORCLUTCHRELAY
30 - COMMON FEED 85 - COIL GROUND 86 - COIL BATTERY 87 - NORMALLY OPEN 87A - NORMALLY CLOSED
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is connected to fused battery feed. There should be bat- tery voltage at the cavity for relay terminal 30 at all times. If OK, go to Step 2. If not OK, repair the open circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is connected to the compressor clutch coil. There should be continuity between this cavity and the A/C com- pressor clutch relay output circuit cavity of the com- pressor clutch coil wire harness connector. If OK, go to Step 4. If not OK, repair the open circuit as required.
(4) The relay coil battery terminal
is con- nected to the fused ignition switch output (run/start) circuit. There should be battery voltage at the cavity
(86)
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24 - 14
A/C COMPRESSOR CLUTCH RELAY (Continued)DR
for relay terminal 86 with the ignition switch in the On position. If OK, go to Step 5. If not OK, repair the open circuit to the fuse in the junction block as required.
(5) The coil ground terminal cavity (85) is switched to ground through the Powertrain Control Module (PCM). There should be continuity between this cav- ity and the A/C compressor clutch relay control cir- cuit cavity of the PCM wire harness connector C (gray) at all times. If not OK, repair the open circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
Center (PDC).
(2) Remove the cover from the Power Distribution
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.
(4) Unplug the compressor clutch relay from the
PDC.
INSTALLATION
(1) Install the compressor clutch relay by aligning the relay terminals with the cavities in the PDC and pushing the relay firmly into place.
(2) Install the PDC cover. (3) Connect the battery negative cable. (4) Test the relay operation.
A/C HEATER CONTROL DESCRIPTION
The A/C heater system uses a seriers of electrical controls. These controls provide the vehicle operator with a number of setting options to help control the climate and comfort within the vehicle. Refer to the owner’s manual in the vehicle glove box for more information on the features, use, and suggested oper- ation of these controls.
The A/C heater control - (Single Zone) or (Dual Zone) panel is located to the right of the instrument cluster on the instrument panel.
The control panel contains a rotary-type tempera- ture control, a rotary-type mode control switch knob, and a rotary-type blower motor speed switch knob. The control also has a push button to activate the Optional side view mirrors defroster elements and to turn the A/C on.
The Dual Zone HVAC control panel contains a pair of slider-type temperature controls, a rotary-type mode control switch knob and a rotary-type blower motor speed switch knob. The control also has but- tons to turn the A/C ON, Set it on Max A/C and for the Optional Heated Sideview Mirrors.
The A/C heater control panel cannot be repaired. If faulty or damaged, the entire unit must be replaced. The illumination lamps are available for service replacement.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR- BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center bezel from the instrument panel(Refer to 23 - BODY/INSTRUMENT PANEL/IN- STRUMENT PANEL CENTER BEZEL - REMOVAL). (3) Remove the screws that secure the A/C Heater control to the instrument panel (Fig. 11) or (Fig. 12). (4) Pull the A/C Heater control assembly away from the instrument panel far enough to access the connections on the back of the control.
Fig.11SingleZoneHVACControl
1 - Mounting Tab (4) 2 - A/C Button 3 - Sideview Mirror Defroster Button (if equiped) 4 - Mode Control 5 - Blend Air Control 6 - Blower Motor Speed Control
(5) Unplug the wire harness connectors from the
back of the A/C Heater control (Fig. 13).
DR A/C HEATER CONTROL (Continued)
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24 - 15
A/C PRESSURE TRANSDUCER DESCRIPTION - A/C PRESSURE TRANSDUCER The A/C pressure transducer is a switch that is installed on a fitting located on the refrigerant dis- charge line between the compressor and the conden- sor in the front corner of the engine compartment. An internally threaded hex fitting on the transducer con- nects it to the externally threaded Schrader-type fit- ting on the liquid line. A rubber O-ring seals the connection between the transducer and the discharge line fitting. Three terminals within a molded plastic connector receptacle on the top of the transducer con- nect it to the vehicle electrical system through a take out and connector of the headlamp and dash wire harness.
The A/C pressure transducer cannot be adjusted or it must be
faulty or damaged,
if
repaired and, replaced.
OPERATION
The A/C pressure transducer monitors the pres- sures in the high side of the refrigerant system through its connection to a fitting on the discharge line. The transducer will change its internal resis- tance in response to the pressures it monitors. The Powertrain Control Module (PCM) provides a five volt reference signal and a sensor ground to the transducer, then monitors the output voltage of the transducer on a sensor return circuit to determine refrigerant pressure. The PCM is programmed to respond to this and other sensor inputs by controlling the operation of the air conditioning compressor clutch and the radiator cooling fan to help optimize air conditioning system performance and to protect the system components from damage. The A/C pres- sure transducer input to the PCM will also prevent the air conditioning compressor clutch from engaging when ambient temperatures are below about 10° C due to the pressure/temperature relationship of the refrigerant. The Schrader-type valve in the discharge line fitting permits the A/C pressure transducer to be removed or installed without disturbing the refriger- ant in the system. The A/C pressure transducer is diagnosed using a DRBIIIt scan tool. Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - A/C PRESSURE TRANSDUCER
The A/C pressure transducer is tested using a DRBIIIt scan tool. Refer to the appropriate diagnos- tic information. Before testing the A/C pressure transducer, be certain that the transducer wire har- ness connection is clean of corrosion and properly connected. For the air conditioning system to operate,
Fig.12DualZoneA/CControl
1 - A/C Button 2 - Max. A/C Button 3 - Sideview Mirror Defrost Button (if equiped) 4 - Mounting Tabs (4) 5 - Driverside Temperature Control 6 - Passengerside Temperature Control 7 - Mode Control 8 - Blower Motor Speed Control
Fig.13HVACControl-(RearView-typical)
1 - Mounting Tabs (4) 2 - Mounting Screws (4) 3 - HVAC Control Connector 4 - Heated Sideview Mirror Connector 5 - HVAC Control Assembly
INSTALLATION
(1) Plug the two wire harness connectors into the
back of the A/C Heater control.
(2) Position the A/C Heater control in the instru- ment panel bezel and secure it with four screws. Tighten the screws to 2.2 N·m (20 in. lbs.).
(3) Reinstall the center bezel onto the instrument panel(Refer to 23 - BODY/INSTRUMENT PANEL/IN- STRUMENT PANEL CENTER BEZEL - INSTALLA- TION).
(4) Connect the battery negative cable.
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24 - 16
A/C PRESSURE TRANSDUCER (Continued)an A/C pressure transducer voltage reading between 0.451 and 4.519 volts is required. Voltages outside this range indicate a low or high refrigerant system pressure condition to the Powertrain Control Module (PCM). The PCM is programmed to respond to a low or high refrigerant system pressure by suppressing operation of the compressor. Refer to the A/C Pres- sure Transducer Voltage table for the possible condi- tion indicated by the transducer voltage readings.
A/C PRESSURE TRANSDUCER VOLTAGE POSSIBLE INDICATION
VOLTAGE
0.0
0.150 TO 0.450
0.451 TO 4.519
4.520 TO 4.850
5.0
REMOVAL
1. NO SENSOR SUPPLY VOLTAGE FROM PCM. 2. SHORTED SENSOR CIRCUIT. 3. FAULTY TRANSDUCER. 1. AMBIENT TEMPERATURE BELOW 10° C (50° F). 2. LOW REFRIGERANT SYSTEM PRESSURE. 1. NORMAL REFRIGERANT SYSTEM PRESSURE. 1. HIGH REFRIGERANT SYSTEM PRESSURE. 1. OPEN SENSOR CIRCUIT. 2. FAULTY TRANSDUCER.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connector for the A/C pressure transducer from the transducer connec- tor receptacle.
(3) Using an open end wrench, unscrew the A/C pressure transducer from the fitting on the discharge line between the compressor and the condenser.
(4) Remove the seal from the A/C pressure trans-
ducer fitting and discard.
INSTALLATION
(1) Lubricate a new rubber O-ring seal with clean it on the A/C pressure
refrigerant oil and install transducer fitting.
(2) Using an open end wrench, install and tighten the A/C pressure transducer onto the fitting on the discharge line between the compressor and the con- denser.
(3) Reconnect the wire harness connector for the A/C pressure transducer to the transducer connector receptacle.
(4) Reconnect the battery negative cable.
DR
BLEND DOOR ACTUATOR DESCRIPTION
The blend door actuators are reversible, 12-volt Direct Current (DC), servo motors. Models with the single zone heater and air conditioner system have a single blend air door, which is controlled by a single blend door actuator. Models with the optional dual zone front heater and air conditioner system have dual blend air doors, which are controlled by two blend door actuators. The single zone blend door actuator is located on the driver side end of the heat- er-A/C housing unit, close to the dash panel. In the dual zone system, the same blend door actuator used for the single zone system becomes the driver side blend door actuator, and is mechanically connected to only the driver side blend air door. In the dual zone system, a second separate blend door actuator is also located on the top of the heater-A/C housing unit and is mechanically connected to only the passenger side blend air door.
The blend door actuators are interchangeable with each other, as well as with the actuators for the mode door and the recirculation air door. Each actua- tor is contained within an identical black molded plastic housing with an integral wire connector receptacle. Two integral mounting tabs allow the actuator to be secured with two screws to the heater- A/C unit housing. Each actuator also has an identical output shaft with splines that connects it to the link- age that drives the proper blend air door. The blend door actuators do not require mechanical indexing to the blend door linkage, as they are electronically cal- ibrated by the heater-A/C control module. The blend door actuators cannot be adjusted or repaired and, if damaged or faulty, they must be replaced.
OPERATION
Each blend door actuator is connected to the heat- er-A/C control module through the vehicle electrical system by a dedicated two-wire take out and connec- tor of the HVAC wire harness. The blend door actua- tor can move the blend air door in two directions. When the heater-A/C control module pulls the volt- age on one side of the motor connection high and the other connection low, the blend air door will move in one direction. When the module reverses the polarity of the voltage to the motor, the blend air door moves in the opposite direction. When the module makes the voltage to both connections high or both connec- tions low, the blend air door stops and will not move. These same motor connections also provide a feed- back signal to the heater-A/C control module. This feedback signal allows the module to monitor the operation and relative positions of the blend door actuator and the blend air door. The heater-A/C con-
DR BLEND DOOR ACTUATOR (Continued)
trol module learns the blend air door stop positions during the calibration procedure and will store a Diagnostic Trouble Code (DTC) for any problems it detects in the blend door actuator circuits. The blend door actuator can be diagnosed using a DRBIIIt scan tool. Refer to the appropriate diagnostic information.
REMOVAL
The single zone heating and air conditioning sys- tem is equipped with a single blend door actuator. The dual zone system has two blend door actuators, one for the driver side blend air door and one for the passenger side blend air door. The same service pro- cedures can be used for each of these actuators.
WARNING: ON VEHICLES EQUIPPED WITH AIR- BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN ACCIDENTAL AIR- BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel assembly(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Disconnect the HVAC wire harness connector for the blend door actuator from the actuator connec- tor receptacle. (Fig. 14)
(4) Remove the screws that secure the blend door
actuator to the distribution housing.
(5) Remove the blend door actuator from the dis-
tribution housing.
INSTALLATION
(1) Position the blend door actuator into the heat- er/air conditioner housing. If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those in the blend air door linkage. (2) Install and tighten the three screws that secure the blend door actuator to the distribution housing. Tighten the screws to 2 N·m (17 in. lbs.).
(3) Reconnect the HVAC wire harness connector for the blend door actuator to the actuator connector receptacle.
(4) Install the instrument panel assembly(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL ASSEMBLY - INSTALLATION).
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24 - 17
Fig.14HVACHousing-DualZoneShown(Typical-
SingleZone)
1 - Mounting Nut 2 - Passenger Blend Door Actuator (dual zone) 3 - Mounting Nut 4 - Air Intake Spacer 5 - Recirculation Door Actuator 6 - Recirculation Door Assembly 7 - Driver Side Blend Door Actuator 8 - HVAC Housing 9 - Mounting Screw 10 - Defroster Door Actuator 11 - Panel Actuator
(5) Reconnect the battery negative cable. (6) Perform the heater-A/C control calibration pro- cedure. (Refer to 24 - HEATING & AIR CONDITION- ING/CONTROLS - FRONT/A/C-HEATER CONTROL - STANDARD PROCEDURE - HEATER-A/C CON- TROL CALIBRATION).
BLOWER MOTOR RESISTOR BLOCK DESCRIPTION
The blower motor resistor is mounted to the rear side of the HVAC housing on the passenger side of the vehicle.
OPERATION
The resistor is a ceramic resistor that utilizes resistor circuit tracers to reduce current flow to the
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24 - 18
BLOWER MOTOR RESISTOR BLOCK (Continued)DR
blower. The blower motor switch directs the ground path through the correct resistor circuit to obtain the selected speed.
The blower motor resistor cannot be repaired and,
if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR RESISTOR
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR- BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Reach under the passenger side bottom of the HVAC unit and unplug the wire harness connector from the blower motor resistor.
(3) Check for continuity between each of
the blower motor switch input terminals of the resistor and the resistor output terminal. In each case there should be continuity. If OK, repair the wire harness circuits between the blower motor switch and the blower motor resistor or blower motor relay as required. If not OK, replace the faulty blower motor resistor.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR- BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) The blower motor resistor is accessable from the passenger side of the HVAC unit and is located on the bottom of the HVAC unit.
(3) Pull out the lock on the blower motor resistor wire harness connector to unlock the connector latch. (4) Depress the latch on the blower motor resistor wire harness connector and unplug the connector from the resistor.
(5) Remove the two screws that secure the resistor
to the HVAC housing.
(6) Remove the resistor from the HVAC housing.
INSTALLATION
(1) Install the new resistor in the HVAC housing. (2) Install the two screws that secure the resistor to the HVAC housing and tighten to 2.2 N·m (20 in. lbs.).
(3) Plug in the blower motor harness connector. (4) Push in the lock on the blower motor resistor
harness connector.
(5) Close the glove box door. (6) Connect the battery negative cable.
BLOWER MOTOR SWITCH DESCRIPTION
The A/C Heater blower motor is controlled by a four position rotary-type blower motor switch, mounted in the A/C Heater control panel. The switch allows the selection of one of four blower motor speeds, but can only be turned off by selecting the Off position on the blower motor switch.
OPERATION
The blower motor switch directs the blower motor ground path through the mode control switch to the blower motor resistor, or directly to ground, as required to achieve the selected blower motor speed. The blower motor switch cannot be repaired and, if faulty or damaged, the entire A/C Heater control unit must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
DR BLOWER MOTOR SWITCH (Continued)
WARNING: ON VEHICLES EQUIPPED WITH AIR- BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
