Automatic switch JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

(6) Reach through the front bin opening of the
floor console to access and tighten the two nuts that
secure the center floor tunnel bracket to the studs on
the floor panel transmission tunnel. Tighten the nuts
to 11.8 N´m (105 in. lbs.).
(7) Reinstall the front bin into the floor console.
(Refer to 23 - BODY/INTERIOR/FLOOR CONSOLE -
INSTALLATION).
(8) Install and tighten all of the screws that secure
the perimeter of the top pad to the instrument panel
structural duct. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(9) Install and tighten the four screws that secure
the heater-A/C control to the instrument panel struc-
tural duct. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(10) Install and tighten the four screws that secure
the radio to the instrument panel structural duct.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(11) Reinstall the center lower bezel onto the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/IP CENTER BEZEL - LOWER -
INSTALLATION).
(12) Reinstall the center upper bezel onto the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/IP CENTER BEZEL - UPPER -
INSTALLATION).
(13) Install and tighten the two large screws on
the glove box opening upper reinforcement that
secure the top pad to the instrument panel structural
duct (Fig. 24). Tighten the screws to 11.8 N´m (105
in. lbs.).
(14) Install and tighten the two small screws on
the glove box opening upper reinforcement that
secure the panel outlets to the instrument panel
structural duct. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(15) Reinstall the glove box lamp and switch into
the instrument panel. (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/GLOVE BOX
LAMP/SWITCH - INSTALLATION).
(16) Reinstall the lower right center bezel onto the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/IP LOWER RIGHT CENTER BEZEL
- INSTALLATION).(17) Reinstall the end cap onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL END CAP - INSTALLA-
TION).
(18) Roll the glove box back up into the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - STANDARD PROCEDURE - GLOVE
BOX ROLL DOWN).
(19) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(20) Reinstall the instrument cluster into the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(21) Reinstall the cluster bezel onto the instru-
ment panel. (Refer to 23 - BODY/INSTRUMENT
PANEL/CLUSTER BEZEL - INSTALLATION).
(22) If the vehicle is so equipped, position the
automatic headlamp light sensor/vehicle theft secu-
rity system indicator unit to the instrument panel
top pad just outboard of the driver side defroster out-
let. Install and tighten the two screws that secure
the sensor/indicator unit. Tighten the screws to 2.2
N´m (20 in. lbs.).
(23) Engage the retainer that secures each of the
two instrument panel wire harness speaker take outs
to the mounting hole in the instrument panel top
pad.
(24) Reinstall the speakers onto the instrument
panel top pad. (Refer to 8 - ELECTRICAL/AUDIO/
SPEAKER - INSTALLATION - INSTRUMENT
PANEL SPEAKER).
(25) Install and tighten the four nuts that secure
the instrument panel top pad to the studs on the
dash panel near the windshield fence line (Fig. 23).
Tighten the nuts to 11.8 N´m (105 in. lbs.).
(26) Reinstall the top cover onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL TOP COVER - INSTALLA-
TION).
(27) Reinstall the trim onto the right and left
A-pillars. (Refer to 23 - BODY/INTERIOR/A-PILLAR
TRIM - INSTALLATION).
(28) Reconnect the battery negative cable.
WJINSTRUMENT PANEL SYSTEM 23 - 55
INSTRUMENT PANEL TOP PAD (Continued)

SUNROOF
TABLE OF CONTENTS
page page
SUNROOF
DESCRIPTION.........................96
DIAGNOSIS AND TESTING - SUNROOF......96
DRAIN TUBE
REMOVAL............................100
INSTALLATION........................100
CONTROL MODULE
REMOVAL............................101
INSTALLATION........................101
DRIVE MOTOR
REMOVAL............................101
INSTALLATION........................101
WIND DEFLECTOR
REMOVAL............................102INSTALLATION........................102
GLASS PANEL
REMOVAL............................102
INSTALLATION........................103
ADJUSTMENTS
ADJUSTMENTS - FIT.................103
ADJUSTMENT - TIMING...............103
SUNSHADE
REMOVAL............................103
INSTALLATION........................103
HOUSING ASSEMBLY
REMOVAL............................104
INSTALLATION........................104
SUNROOF
DESCRIPTION
WARNING: Keep fingers and other body parts out
of sunroof opening at all times.
The sunroof features a power sliding glass panel
and a sunshade which can be manually positioned
anywhere along its travel, rearward of glass panel
front edge.
The sunroof is electrically operated from a switch
located on the mini overhead console. To operate the
sunroof the ignition switch must be in the On/Run
position. The sunroof has both manual and Express
Open modes of operation when opening. To open the
sunroof in the Express Open mode, the switch is
pressed rearward for less than1 second.This causes
the sunroof glass to automatically retract and stop at
a position slightly forward of full open that reduces
low speed wind buffeting. The sunroof can also be
opened manually by pressing and holding the switch
rearward. Once the switch is held reward for more
than1 second,the glass will retract in the manual
mode. Releasing the switch at any time during travel
will cause the sunroof to stop at the current position.
To close the sunroof from an open position, the
switch must be pushed forward and held until the
sunroof glass comes to a complete stop. Releasing the
switch at any time in this mode will cause the sun-
roof to stop at the current position.
To vent the sunroof from the closed position, the
switch is pushed forward and held. Releasing theswitch at any time during travel will cause the sun-
roof to stop at the current vent position. To reach the
fully vented position, continue to hold the switch for-
ward until vent motion stops. To close the sunroof
from the vent position, push and hold the switch
rearward until the glass comes to a complete stop.
DIAGNOSIS AND TESTING - SUNROOF
CAUTION: The sunroof motor is only to be powered
through the vehicle battery and vehicle wire har-
ness. Applying power to the sunroof motor leads
will cause failure of the sunroof control unit.
Before beginning sunroof diagnostics verify that all
other power accessories are in proper operating con-
dition. Refer to Sunroof Diagnostic Chart for possible
causes. If not, a common electrical problem may
exist. Refer to Group 8W, Wiring Diagrams, of this
publication for circuit, splice and component descrip-
tions. Check the condition of the circuit protection
(20 amp high current fuse (battery feed) located in
the Power Distribution Center (PDC). Check the
cover of the PDC for location of the fuse. Check for
correct operation of the sunroof delay relay. Inspect
all wiring connector pins for proper engagement and
continuity. Check for battery voltage at battery and
ignition pins of the power sunroof express module
wiring connector. Refer to Group 8W, Wiring Dia-
grams, for circuit information. The controller will not
operate at less than 10 volts. Check the ground at
the sunroof express module.
Before beginning diagnosis for wind noise or water
leaks, verify that the problem was not caused by
23 - 96 SUNROOFWJ

releasing the control switch before the sunroof was
fully closed. The sunroof module has a water-man-
agement system. During washing high-pressure
water may be forced between the glass panel seal
and the roof opening. Normally this water will drain.
However, when some type of drying blower system is
used, like those found in automatic car washes, thewater may not have a chance to drain before the
blower forces air between the seal and the roof open-
ing. This causes the water to blow over the edge of
the module and onto the headlining.
Refer to (Fig. 1) Sunroof Assembly for exploded
view of the sunroof.
SYMPTOM STEP POSSIBLE CAUSE
Sunroof squeaks when
opening/closing.1 Identify if the cause is a seal squeak. If seal is worn, replace the
seal.
2 Check seal compression for uniformity in opening, If not uniform,
glass is not centered in opening.
3 Re-center glass by repositioning module in opening.
4 Identify if mechanism squeaks.
5 Check for lubrication, re-lube if necessary.
6 Check for dirt/debris in tracks, clean and re-lube.
7 Identify if motor squeaks, replace the motor.
Water leaks into the vehicle. 1 Check for a good connection at the drain tubes, re-connect where
needed.
2 Check for plugged/pinched hoses throughout.
3 Adjust the glass panel. Refer to glass panel adjustments in this
section.
4 Check seal for wear/damage, replace glass as necessary.
Motor inoperative. 1 Check connectors at the motor, switch, control module and power
source.
2 Check for defective control module, replace if necessary.
3 Replace the motor.
Motor noise when opening/
closing.1 Identify if motor noise, replace motor.
2 Insure noise is from the motor and not cables, (cable ratcheting).
Grinding noise when opening/
closing.1 Identify if the motor is grinding, replace motor.
(Mechanism noise, scraping.) 2 Check for lubrication in tracks and mechanism, re-lube if
necessary.
3 Check for dirt/debris in tracks, clean and re-lube.
(Cable ratcheting.) 4 Cables ratchet at the motor pinion; mechanism jammed, fix
mechanism and replace cables and motor bracket.
Wind noise when sunroof fully
closed.1 Check seal compression for uniformity in opening, If not uniform,
glass is not centered in opening.
2 Glass not adjusted flush to roof. Refer to glass panel adjustments
in this section.
3 Mechanism not fully closed.
A) Motor out of time, re-time motor/mechanism. Refer to glass
panel adjustments in this section.
B) Cable ratcheting, replace cables and motor bracket.
4 Seal worn, replace glass.
Sunroof will not open/close. 1 Check switch and switch connection.
WJSUNROOF 23 - 97
SUNROOF (Continued)

CONTROL MODULE
REMOVAL
(1) Move the glass panel to the fully closed posi-
tion.
(2) Remove the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - REMOVAL)
(3) Remove the sun visors. (Refer to 23 - BODY/
INTERIOR/SUN VISOR - REMOVAL)
(4) Remove the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - REMOVAL)
(5) Lower headliner as necessary to gain access to
the sunroof express module.
(6) Disconnect the express module wire harness
connectors.
(7) Remove express module screw.
(8) Remove express module from the keyway by
sliding module towards the center of the vehicle.
INSTALLATION
(1) Insert sunroof express module in the keyway
located in the sunroof module and slide the module
outward to lock it into position.
(2) Install the sunroof express module screw.
(3) Connect the wire connectors to the sunroof
express module.
(4) Install the headliner into position.
(5) Install the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION)
(6) Install the sun visors. (Refer to 23 - BODY/IN-
TERIOR/SUN VISOR - INSTALLATION)
(7) Install the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - INSTALLATION)
(8) Test sunroof operation, adjust if necessary.
(Refer to 23 - BODY/SUNROOF/GLASS PANEL -
ADJUSTMENTS)
DRIVE MOTOR
REMOVAL
CAUTION: The sunroof system is timed from the
factory so that the motor shuts off automatically
when the sunroof window reaches a certain posi-
tion. Extreme care must be taken when removing
the motor, timing may be thrown off causing possi-
ble damage to the sunroof system. Anytime the
motor is removed from the sunroof assembly the
sunroof glass panel must be in the FULLY CLOSED
POSITION or the unit will be out of timing. The drive
motor cannot be reset to the park position after
being removed.CAUTION: The sunroof motor should only be pow-
ered through the vehicle battery and sunroof wire
harness. Applying power to the sunroof motor leads
will cause failure of the control module.
(1) Move glass panel to the fully closed position.
(2) Remove the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - REMOVAL)
(3) Remove the B-pillar upper trim. (Refer to 23 -
BODY/INTERIOR/B-PILLAR UPPER TRIM -
REMOVAL)
(4) Remove the C-pillar trim. (Refer to 23 - BODY/
INTERIOR/C-PILLAR TRIM - REMOVAL)
(5) Remove the D-pillar trim. (Refer to 23 - BODY/
INTERIOR/D-PILLAR TRIM - REMOVAL)
(6) Remove the sunvisors. (Refer to 23 - BODY/IN-
TERIOR/SUN VISOR - REMOVAL)
(7) Remove the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - REMOVAL)
(8) Disconnect the control switch wire connector.
(9) Remove headliner as necessary to gain access
to sunroof drive motor. Refer to Headliner Removal
and Installation for proper procedures.
(10) Disconnect the drive motor wire harness con-
nectors (Fig. 3).
(11) Remove drive motor fasteners and remove
motor from the sunroof housing.
INSTALLATION
(1) Ensure that the window is in the fully closed
position before mounting the motor. If motor fails
with the window in the open position the sunroof
glass panel timing will have to be timed. The new
motor comes in the fully closed position and with a
gage for setting cable timing. (Refer to 23 - BODY/
SUNROOF/GLASS PANEL - ADJUSTMENTS - TIM-
ING)
(2) Place drive motor into position on the sunroof
housing and install fasteners.
Fig. 3 Sunroof Drive Motor and Express Module
1 - EXPRESS MODULE
2 - SCREW
WJSUNROOF 23 - 101

OPERATION
OPERATION - HEATER AND AIR CONDITIONER
Outside fresh air enters the vehicle through the
cowl top opening at the base of the windshield, and
passes through a plenum chamber to the HVAC sys-
tem blower housing. Air flow velocity can then be
adjusted with the blower motor speed selector switch
on the a/c heater control panel. The air intake open-
ings must be kept free of snow, ice, leaves, and other
obstructions for the HVAC system to receive a suffi-
cient volume of outside air.
It is also important to keep the air intake openings
clear of debris because leaf particles and other debris
that is small enough to pass through the cowl ple-
num screen can accumulate within the HVAC hous-
ing. The closed, warm, damp and dark environment
created within the HVAC housing is ideal for the
growth of certain molds, mildews and other fungi.
Any accumulation of decaying plant matter provides
an additional food source for fungal spores, which
enter the housing with the fresh air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during HVAC sys-
tem operation.
Both the manual and AZC heater and air condi-
tioner are blend-air type systems. In a blend-air sys-
tem, a blend door controls the amount of
unconditioned air (or cooled air from the evaporator)
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 tempera-
ture by energizing the blend door actuator, which
operates the blend door. This allows an almost imme-
diate control of the output air temperature of the sys-
tem. The AZC system will have separate blend doors
and temperature controls for each front seat occu-
pant.
The mode control knob on the a/c heater control
panel is used to direct the conditioned air to the
selected system outlets. On manual temperature con-
trol systems, the mode control knob switches engine
vacuum to control the mode doors, which are oper-
ated by vacuum actuators. On AZC systems, the
mode control knob switches electrical current to con-
trol the mode doors, which are operated by electronic
actuators.
The outside air intake can be shut off on manual
temperature control systems by selecting the Recircu-
lation Mode with the mode control knob. The outside
air intake can be shut off on Automatic Zone Control
(AZC) type system by pushing the Recirculation
Mode button. This will operate the recirculation door
that closes off the outside fresh air intake and recir-
culates 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 ther-
mal expansion valve to meter refrigerant flow to the
evaporator coil. To maintain minimum evaporator
temperature and prevent evaporator freezing, the
system utilizes an evaporator thermister probe with
the appropriate operating logic located in the body
control module (BCM).
OPERATION - REFRIGERANT SYSTEM SERVICE
PORT
The high pressure service port is located on the liq-
uid line near the receiver/drier. The low pressure ser-
vice port is located on the suction line near the
evaporator at the rear of the engine compartment.
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.
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 specific humidity air. The evaporator, located
in the HVAC housing on the dash panel below the
instrument panel, is cooled to temperatures near the
freezing 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 tempera-
ture of the air delivered to the interior of the vehicle. It
is important to understand the effect that humidity has
on the performance of the air conditioning 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 evaporator fins. Condensing the
moisture in the air transfers heat energy into the evap-
orator 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.
24 - 2 HEATING & AIR CONDITIONINGWJ
HEATING & AIR CONDITIONING (Continued)

However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
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 their
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.
If the vehicle has the optional Automatic Zone Control
(AZC) system, and has intermittent operational prob-
lems or fault codes, be certain that the wire harness
connectors on the HVAC housing are properly seated
(Fig. 2). To check this condition, unplug the two wire
harness connector halves, then plug them in again.
Before performing the following procedure, (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - CAUTION) (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING). The air
temperature in the test room and in the vehicle must
be a minimum of 21É C (70É F) for this test.
(1)
Connect a tachometer and a manifold gauge set.
(2) If the vehicle has the standard manual temper-
ature control, set the A/C Heater mode control switch
knob in the Panel position, the temperature control
knob in the full cool (Fresh Air Mode) position, the
A/C button in the On position, and the blower motor
switch knob in the highest speed position. If the vehi-
cle has the optional AZC, set the A/C Heater mode
control switch knob in the Panel position, the tem-
perature control knob in the full cool position, the
A/C button in the On position, and the blower motor
switch knob in the highest (manual) speed position.
(3) Start the engine and hold the idle at 1,300 rpm
with the compressor clutch engaged.
(4) The engine should be at operating temperature.
The doors and windows must be open.
(5)
Insert a thermometer in the driver side center
A/C (panel) outlet. Operate the engine for five minutes.
(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 - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE).
Performance Temperature and Pressure
Ambient Air Temperature
and Humidity21É C
(70É F @ 80%
humidity)27É C
(80É F @ 80%
humidity)32É C
(90É F @ 80%
humidity)38É C
(100ÉF@50%
humidity)43É C
110É F @ 20%
humidity)
Air Temperature at Center
Panel Outlet10 to 13É C
(50 to 55É F)14 to 17É C
(58 to 63É F)15 to 18É C
(60 to 65É F)17 to 20É C
(63 to 68É F)14 to 17É C
(58 to 63É F)
Evaporator Inlet Pressure
at Charge Port241 to 276 kPa
(35 to 40 psi)262 to 290 kPa
(38 to 42 psi)269 to 296 kPa
(39 to 43 psi)275 to 303 kPa
(40 to 44 psi)262 to 290 kPa
(38 to 42 psi)
Compressor Discharge
Pressure1241 to 1792
kPa
(180 to 260 psi)1380 to 1930
kPa
(200 to 280 psi)1380 to 1930
kPa
(200 to 280 psi)1655 to 2206
kPa
(240 to 320 psi)1567 to 2068
kPa
(220 to 300 psi)
Note: The discharge air temperatures will be lower if the humidity is less than the percentages shown.
Fig. 2 HVAC Housing - (rear view)
1 - Instrument Panel
2 - Air Intake
3 - Expansion Valve
4 - HVAC Housing
5 - Heater Core Input/Output Ports
6 - Instrument Panel Wiring Harness
7 - Blower Motor
WJHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)

(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 connection 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, and test affected sys-
tems.SPECIFICATIONS
A/C APPLICATION TABLE
Item Description Notes
VEHICLE WJ - Grand
Cherokee
SYSTEM R134a w/
expansion valve
COMPRESSOR Nippondenso
10PA17ND-8 PAG oil
Freeze±up
ControlEvaporator Probe Evaporator
mounted
Low psi Control opens < 22 psi -
resets > 34-38 psi
High psi Control opens > 450-490
psi - resets <
270-330 psiline mounted
CONTROL
HEADManual type manual
controls
Automatic Zone
Control (AZC)Automatic
Zone Control
(AZC) with
dual infrared
sensing
Mode Doors Vacuum actuators
(manual)electric
actuator
(AZC)
Blend Door Electric actuator (manual and
AZC)
Blend Door
(passenger)Electric actuator (AZC only)
Recirculation
DoorVacuum actuator
(manual)electric
actuator
(AZC)
Blower Motor Hardwired to
control head
resistor block
(manual),
blower
controller (AZC)
COOLING FAN Hybrid - viscous
clutch/electricPCM output
CLUTCH
Control Relay PCM
controlled
Draw
2.0-3.9 amps @ 12 V  0.5V@ 70É F
Gap 0.0169-0.0319
DRB IIIT
Reads TPS, RPM, A/C
switch
Actuators Clutch relay
WJHEATING & AIR CONDITIONING 24 - 7
HEATING & AIR CONDITIONING (Continued)

CONTROLS
TABLE OF CONTENTS
page page
CONTROLS
DIAGNOSIS AND TESTING - VACUUM
SYSTEM............................10
A/C COMPRESSOR CLUTCH
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL........................13
STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN....................14
REMOVAL.............................14
INSPECTION..........................15
INSTALLATION.........................15
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH RELAY..........16
REMOVAL.............................17
INSTALLATION.........................17
A/C HEATER CONTROL
DESCRIPTION.........................17
OPERATION...........................17
DIAGNOSIS AND TESTING - AUTOMATIC
ZONE CONTROL SYSTEM..............18
REMOVAL.............................24
INSTALLATION.........................25
A/C PRESSURE TRANSDUCER
DESCRIPTION.........................25
OPERATION...........................25
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER.......................26
REMOVAL.............................26
INSTALLATION.........................26
BLOWER MOTOR CONTROLLER
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................27
INSTALLATION.........................27
BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION.........................27
OPERATION...........................27
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR BLOCK..............27
REMOVAL.............................28
INSTALLATION.........................28BLOWER MOTOR SWITCH
DESCRIPTION.........................28
OPERATION...........................28
DIAGNOSIS AND TESTING - BLOWER
MOTOR SWITCH-MANUAL TEMPERATURE
CONTROL SYSTEM....................28
REMOVAL.............................29
IN-CAR TEMPERATURE SENSOR
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................29
BLEND DOOR ACTUATOR
DESCRIPTION.........................30
REMOVAL.............................30
INSTALLATION.........................30
MODE DOOR ACTUATOR
DESCRIPTION.........................30
REMOVAL
REMOVAL - HEAT/DEFROST - PANEL/
DEFROST DOOR ELECTRIC ACTUATOR . . . 31
REMOVAL - HEAT/DEFROST DOOR
VACUUM ACTUATOR..................31
REMOVAL - PANEL/DEFROST DOOR
VACUUM ACTUATOR..................32
INSTALLATION
INSTALLATION - HEAT/DEFROST -
PANEL/DEFROST DOOR ELECTRIC
ACTUATOR..........................32
INSTALLATION - HEAT/DEFROST DOOR
VACUUM ACTUATOR..................33
INSTALLATION - PANEL/DEFROST DOOR
VACUUM ACTUATOR..................33
RECIRCULATION DOOR ACTUATOR
DESCRIPTION.........................33
REMOVAL
REMOVAL - RECIRCULATION DOOR
VACUUM ACTUATOR..................33
REMOVAL - RECIRCULATION DOOR
ELECTRIC ACTUATOR.................33
INSTALLATION
INSTALLATION - RECIRCULATION DOOR
VACUUM ACTUATOR..................34
INSTALLATION - RECIRCULATION DOOR
ELECTRIC ACTUATOR.................34
VACUUM CHECK VALVE
DESCRIPTION.........................34
OPERATION...........................34
REMOVAL.............................34
INSTALLATION.........................34
WJCONTROLS 24 - 9

A/C COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a hub bearing and pul-
ley assembly, and a clutch plate (Fig. 4). The
electromagnetic coil unit and the hub bearing and
pulley assembly are each retained on the nose of the
compressor front housing with snap rings. The clutch
plate is keyed to the compressor shaft and secured
with a bolt.
OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley. 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 switch on the a/c heater
control panel, the Automatic Zone Control (AZC) con-
trol module (if the vehicle is so equipped), the evap-
orator probe, the a/c high pressure transducer, the
a/c compressor clutch relay, the body control module
(BCM) and the Powertrain Control Module (PCM).
The PCM may delay compressor clutch engagement
for up to thirty seconds. Refer to Electronic Control
Modules for more information on the PCM controls.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, refer to the
appropriate wiring diagrams. 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, the a/c heater control a/c switch in the ON
position, 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 DRBIIItscan tool and the appro-
priate diagnostic information for testing of the com-
pressor clutch circuit. The following components
must be checked and repaired as required before you
can complete testing of the clutch coil:
²Fuses in the junction block and the Power Dis-
tribution Center (PDC)
²A/C heater mode control switch
²A/C compressor clutch relay
²A/C high pressure transducer
²A/C evaporator probe
²Powertrain Control Module (PCM)
²Body Control Module (BCM)
(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 21É C (70É 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. 4 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - SHAFT KEY
3 - PULLEY
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
WJCONTROLS 24 - 13

gap should be between 0.35 to 0.65 millimeter (0.014
to 0.026 inch). If the proper air gap is not obtained,
add or subtract shims as needed until the desired air
gap is obtained.
(9) Install the compressor shaft bolt. Tighten the
bolt to 13 N´m (115 in. lbs.).
NOTE: The shims may compress after tightening
the shaft bolt. Check the air gap in four or more
places to verify the air gap is still correct. Spin the
pulley before performing a final check of the air
gap.
(10) To complete the installation, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION)
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
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 ISO relay. However, 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.
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 compressor switch on
the a/c heater control panel, the Automatic Zone Con-
trol (AZC) control module (if the vehicle is so
equipped), the a/c fin probe, and the a/c high pres-
sure transducer. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH RELAY - DIAGNOSIS AND TESTING)
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.
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH RELAY
For circuit descriptions and diagrams, refer to the
appropriate wiring information.
The compressor clutch relay (Fig. 10) is located in
the Power Distribution Center (PDC). Refer to the
PDC label for relay identification and location.Remove the relay from the PDC to perform the fol-
lowing tests:
(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.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   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 the Relay Circuit Test procedure
in this group. If not OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, refer to the
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 (86) is con-
nected to the fused ignition switch output (run/start)
circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
Fig. 10 A/C COMPRESSOR CLUTCH RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 16 CONTROLSWJ
A/C COMPRESSOR CLUTCH (Continued)