2003 JEEP GRAND CHEROKEE Passenger seat

SPLICE
NUMBERLOCATION FIG.
S147 (Diesel) In T/O for Controller Anti-Lock Brake 4
S151 In Headlamp Assembly N/S
S152 In Headlamp Assembly N/S
S153 In Headlamp Assembly N/S
S154 In Headlamp Assembly N/S
S155 In Headlamp Assembly N/S
S156 In Headlamp Assembly N/S
S158 4.7L RHD Near T/O for Fuel Injector No. 1 13
S159 In T/O for C101 N/S
S160 (4.7L High
Output)In T/O for C102 N/S
S162 (Diesel) In T/O for Wastegate Solenoid 4, 8
S163 Near T/O for Leak Detection Pump 3
S165 (Diesel) Near T/O for Left Front Wheel Speed Sensor 4
S168 Near T/O for Intake Air Temperature Sensor 7, 8
S169 Near T/O for Engine Control Module C1 7, 8
S170 Near T/O for Engine Control Module C2 7, 8
S171 Near T/O for C113 7
S172 Near T/O for C113 7
S174 Near Washer Fluid Level Switch Connector 3
S176 Near T/O for Intake Air Temperature Sensor 7
S200 In Trough Near T/O for Passenger Heated Seat Switch 21
S200 (RHD) Upper Center Instrument Panel 22
S201 In Trough Near T/O for Front Power Outlet 21
S201 (RHD) Near T/O for Power Connector 22
S202 In Trough Near T/O for Passenger Heated Seat Switch 21
S202 (RHD) Upper Center Instrument Panel 22
S203 In Trough Near T/O for Cigar Lighter 21
S203 (RHD) Lower Center Instrument Panel 22
S204 In Trough Near T/O for Power Connector 21
S204 (RHD) Right Center Instrument Panel 22
S205 Near T/O for Adjustable Pedal Switch 21
S205 (RHD) Upper Center Instrument Panel 22
S206 Near T/O for Adjustable Pedals Switch N/S
S206 (RHD) Upper Center Instrument Panel 22
S207 In Trough Near T/O for Radio Connectors 21
S207 (RHD) Upper Center Instrument Panel 22
S208 In Trough Near T/O for Radio Connectors 21
S208 (RHD) Upper Center Instrument Panel 22
S209 In Trough Near T/O for Left Courtesy Lamp 21
S209 (RHD) Lower Center Instrument Panel 22
S210 In Trough Near T/O for Left Courtesy Lamp 21
8W - 91 - 14 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE
NUMBERLOCATION FIG.
S326 Near T/O for C200 34, 35
S327 Near T/O for c307 34, 35
S328 In Sill Trough Near T/O for G300 34
S329 In Sill Trough Near T/O for G300 34
S330 Near T/O for G300 34
S331 In Sill Trough Near T/O for C303 34, 36
S332 In Sill Trough Near T/O for C303 34, 36
S333 Near T/O for Power Amplifiers 36
S334 In T/O for Power Amplifier - C2 34
S335 Near T/O for C314 36
S336 Near T/O for Driver Power Window Motor 24, 25
S338 Near T/O for Passenger Power Window Motor 26, 27
S339 Near T/O for Passenger Power Window Motor 26 27
S340 In T/O for Passenger Door Module - C1 26, 27
S341 Near T/O for C306 N/S
S345 Near T/O for Sunroof Switch 32
S346 Near T/O for Left Visor/Vanity Lamp 32
S347 Near T/O for Left Visor/Vanity Lamp 32
S348 Near T/O for Automatic Day/Night Mirror 32
S349 Near T/O for Automatic Day/Night Mirror 32
S351 Near T/O for Seat Belt Switch N/S
S352 Near T/O for Seat Belt Switch N/S
S353 Near T/O for Driver Lumbar Switch N/S
S355 Near T/O for C304 and C306 N/S
S356 In T/O for Left Rear Door Lock Motor/Ajar Switch 28
S357 In T/O for Right Rear Door Lock Motor/Ajar Switch 29
S358 Near Left B Pillar Sill Trough 35
S359 Near T/O for C302 34
S360 In T/O for C302 N/S
S362 In T/O for C200 34
S363 In T/O for C200 34
S364 Near B Pillar Sill Trough 36
S365
JapanNear T/O for Remote Keyless Entry Module 24, 25
S366 Near T/O for Junction Block C1 N/S
S367 (RHD) Near T/O for C310 N/S
S368 Near T/O for Power Amplifier - C1 34
S369 Near T/O for Left Visor Vanity Lamp N/S
S370 Near T/O for Sunroof Module 32
S400 Near Rear Window Defogger Ground Connector 38
S401 Near Rear Window Defogger Ground Connector 38
S402 Near T/O for Liftgate Flip-Up Ajar Switch 38
8W - 91 - 16 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

REMOVAL - 4.7L
CAUTION: Be careful not to damage or kink the
cable core wire (within the cable sheathing) while
servicing accelerator pedal or throttle cable.
(1) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer (clip) and throttle cable
core wire from upper end of pedal arm (Fig. 16).
Plastic cable retainer (clip) snaps into pedal arm.
(2) Remove cable core wire at pedal arm.
(3) From inside vehicle, remove clip holding cable
to dashpanel (Fig. 16).
(4) Remove air box at throttle body.
(5) Unsnap cable from plenum routing clip.
(6) Remove cable housing from dash panel and
pull into engine compartment.
(7) Using finger pressure only, disconnect accelera-
tor cable connector at throttle body bellcrank pin by
pushing connector off bellcrank pin towards front of
vehicle (Fig. 38).DO NOT try to pull connector
off perpendicular to the bellcrank pin. Connec-
tor will be broken.(8) Lift accelerator cable from top of cable cam
(Fig. 38).
(9) Press tab (Fig. 39) to release plastic cable
mount from bracket.Press on tab only enough to
release cable from bracket. If tab is pressed too
much, it will be broken.Slide plastic mount (Fig.
39) towards passenger side of vehicle to remove cable
from bracket.
(10) Remove throttle cable from vehicle.
INSTALLATION
INSTALLATION ± 4.0L
(1) Slide throttle cable through hole in bracket
until release tabs lock into bracket.
(2) Connect cable ball end to throttle body
bellcrank ball (snaps on).
(3) Snap cable into routing clips on engine valve
cover.
(4) Slide rubber grommet away from plastic cable
housing.
(5) Install rubber grommet into dash panel until
seated.
(6) Push cable housing into rubber grommet and
through opening in dash panel.
Fig. 37 Throttle (Accelerator) Cable at Throttle
BodyÐ4.0L Engine
1 - ACCELERATOR CABLE
2 - OFF
3 - OFF
4 - THROTTLE BODY BELLCRANK
5 - SPEED CONTROL CABLE
6 - RELEASE TABS
7 - BRACKET
Fig. 38 Accelerator Cable at Bell CrankÐ4.7L V-8
Engine
1 - THROTTLE BODY
2 - SPEED CONTROL CABLE CONNECTOR
3 - OFF
4 - OFF
5 - ACCELERATOR CABLE CONNECTOR
6 - CABLE CAM
7 - BELLCRANK
WJFUEL INJECTION 14 - 55
THROTTLE CONTROL CABLE (Continued)

BODY
TABLE OF CONTENTS
page page
BODY
DIAGNOSIS AND TESTING
WATER LEAKS........................1
WIND NOISE..........................2
STANDARD PROCEDURE
STANDARD PROCEDURE - BODY
LUBRICATION.........................2
STANDARD PROCEDURE - DRILLING AND
WELDING............................3
SPECIFICATIONS
BODY LUBRICANTS....................3
SPECIFICATIONS - TORQUE.............4
SPECIAL TOOLS
BODY...............................4DECKLID/HATCH/LIFTGATE/TAILGATE........5
DOOR - FRONT.........................11
DOORS - REAR.........................19
EXTERIOR.............................25
HOOD.................................33
INSTRUMENT PANEL SYSTEM.............36
INTERIOR..............................69
PAINT.................................81
SEATS................................83
STATIONARY GLASS.....................93
SUNROOF.............................96
WEATHERSTRIP/SEALS..................105
BODY STRUCTURE.....................112
BODY
DIAGNOSIS AND TESTING
WATER LEAKS
Water leaks can be caused by poor sealing,
improper body component alignment, body seam
porosity, missing plugs, or blocked drain holes. Cen-
trifugal and gravitational force can cause water to
drip from a location away from the actual leak point,
making leak detection difficult. All body sealing
points should be water tight in normal wet-driving
conditions. Water flowing downward from the front of
the vehicle should not enter the passenger or luggage
compartment. Moving sealing surfaces will not
always seal water tight under all conditions. At
times, side glass or door seals will allow water to
enter the passenger compartment during high pres-
sure washing or hard driving rain (severe) condi-
tions. Overcompensating on door or glass
adjustments to stop a water leak that occurs under
severe conditions can cause premature seal wear and
excessive closing or latching effort. After completing
a repair, water test vehicle to verify leak has stopped
before returning vehicle to use.
VISUAL INSPECTION BEFORE WATER LEAK TESTS
Verify that floor and body plugs are in place, body
drains are clear, and body components are properly
aligned and sealed. If component alignment or seal-
ing is necessary, refer to the appropriate section of
this group for proper procedures.
WATER LEAK TESTS
WARNING: DO NOT USE ELECTRIC SHOP LIGHTS
OR TOOLS IN WATER TEST AREA. PERSONAL
INJURY CAN RESULT.
When the conditions causing a water leak have
been determined, simulate the conditions as closely
as possible.
²If a leak occurs with the vehicle parked in a
steady light rain, flood the leak area with an open-
ended garden hose.
²If a leak occurs while driving at highway speeds
in a steady rain, test the leak area with a reasonable
velocity stream or fan spray of water. Direct the
spray in a direction comparable to actual conditions.
²If a leak occurs when the vehicle is parked on an
incline, hoist the end or side of the vehicle to simu-
late this condition. This method can be used when
the leak occurs when the vehicle accelerates, stops or
turns. If the leak occurs on acceleration, hoist the
front of the vehicle. If the leak occurs when braking,
hoist the back of the vehicle. If the leak occurs on left
turns, hoist the left side of the vehicle. If the leak
occurs on right turns, hoist the right side of the vehi-
cle. For hoisting recommendations refer to Group 0,
Lubrication and Maintenance, General Information
section.
WATER LEAK DETECTION
To detect a water leak point-of-entry, do a water
test and watch for water tracks or droplets forming
on the inside of the vehicle. If necessary, remove inte-
rior trim covers or panels to gain visual access to the
WJBODY 23 - 1

INSTALLATION
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) Prior to installing the instrument panel into
the vehicle, loosen the three nuts that secure the
instrument panel intermediate bracket and the accel-
erator pedal assembly to the studs on the dash panel
(Fig. 8).
(2) With the aid of an assistant, load the instru-
ment panel assembly through the driver side front
door of the vehicle and hang it on the studs on the
dash panel near the windshield fence line (Fig. 1).
(3) Be certain that the molded plastic hook forma-
tions on the instrument panel structural duct are
inserted into and seated in the guide holes at each
cowl side inner panel.
(4) Loosely install the two screws that secure each
end of the instrument panel to the cowl side inner
panels.
(5) Install and tighten the two screws that secure
the passenger side instrument panel structural duct
to the heater and air conditioner housing (Fig. 13).
Tighten the screws to 11.8 N´m (105 in. lbs.).
(6) Install and tighten the one screw that secures
the instrument panel steering column support
bracket to the driver side end of the heater and air
conditioner housing (Fig. 7). Tighten the screw to
11.8 N´m (105 in. lbs.).
(7) Tighten the two screws that secure each end of
the instrument panel to the cowl side inner panels
(Fig. 10) and (Fig. 14). Tighten the screws to 11.8
N´m (105 in. lbs.).
(8) Install and tighten the one screw that secures
the instrument panel steering column support
bracket to the intermediate bracket on the driver
side dash panel (Fig. 8). Tighten the screw to 11.3
N´m (100 in. lbs.).
(9) Tighten the three nuts that secure the instru-
ment panel intermediate bracket and the accelerator
pedal assembly to the studs on the dash panel.
Tighten the nuts to 11.3 N´m (100 in. lbs.).(10) Install and tighten the four nuts that secure
the instrument panel to the studs on the dash panel
near the windshield fence line. Tighten the nuts to
11.8 N´m (105 in. lbs.).
(11) Install and tighten the nut that secures the
instrument panel steering column support bracket to
the stud on the driver side cowl plenum panel (Fig.
9). Tighten the nut to 28.2 N´m (250 in. lbs.).
(12) Reinstall the instrument panel to center floor
tunnel bracket onto the instrument panel and the
floor panel transmission tunnel. (Refer to 23 - BODY/
INSTRUMENT PANEL/IP CENTER FLOOR TUN-
NEL BRACKET - INSTALLATION).
(13) Reconnect the two instrument panel wire har-
ness connectors to the two heater and air conditioner
housing connectors located near the blower motor on
the passenger side end of the housing (Fig. 12).
(14) Reconnect the two halves of the radio antenna
coaxial cable connector near the right cowl side inner
panel under the end of the instrument panel.
(15) Reconnect the instrument panel wire harness
connector to the lower cavity of the inline connector
on the passenger side cowl side inner panel and
tighten the connector screw (Fig. 11). Tighten the
screw to 4 N´m (36 in. lbs.).
(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) If the vehicle is equipped with the manual
heating and air conditioning system, reconnect the
vacuum harness connector located near the driver
side of the floor panel transmission tunnel behind
the driver side floor duct.
(19) Position the driver side floor duct to the
heater and air conditioner housing near the driver
side of the floor panel transmission tunnel (Fig. 7).
(20) Install and tighten the one screw that secures
the driver side floor duct to the heater and air con-
ditioner housing near the driver side of the floor
panel transmission tunnel. Tighten the screw to 2.2
N´m (20 in. lbs.).
(21) Route the instrument panel wire harness to
the floor panel transmission tunnel and engage the
retainers that secure the harness to the mounting
brackets on the tunnel (Fig. 6).
(22) Install the instrument panel wire harness
ground eyelets to the studs on the floor panel trans-
mission tunnel in front of and behind the airbag con-
trol module and secure the eyelets with nuts. Tighten
the nuts to 7.3 N´m (65 in. lbs.).
WJINSTRUMENT PANEL SYSTEM 23 - 43
INSTRUMENT PANEL SYSTEM (Continued)

INSTALLATION
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) If the vehicle is not equipped with the optional
automatic headlamps light sensor/vehicle theft secu-
rity system indicator, be certain that the hole plug is
installed in the clearance hole located to the out-
board side of the driver side defroster outlet in the
instrument panel top cover (Fig. 22).
(2) Before installing the top cover onto the top of
the instrument panel, be certain that the rubber top
cover seal is properly positioned on the forward edge
of the top cover panel.
(3) Position the top cover onto the top of the
instrument panel.
(4) Align the four snap clips on the top cover with
the snap clip receptacles in the instrument panel top
pad.
(5) Press firmly downward on the top cover over
each of the four snap clip locations until each of the
snap clips is fully seated in their receptacles in the
instrument panel top pad.
(6) Reconnect the battery negative cable.
INSTRUMENT PANEL TOP PAD
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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim from the right and left A-pil-
lars. (Refer to 23 - BODY/INTERIOR/A-PILLAR
TRIM - REMOVAL).
(3) Remove the top cover from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL TOP COVER - REMOVAL).
(4) Remove the four nuts that secure the instru-
ment panel top pad to the studs on the dash panel
near the windshield fence line (Fig. 23).
(5) Remove the speakers from the instrument
panel top pad. (Refer to 8 - ELECTRICAL/AUDIO/
SPEAKER - REMOVAL - INSTRUMENT PANEL
SPEAKER).
(6) Disengage 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. Tuck the loose ends of these speaker take outs
down the defroster ducts to keep them out of the way
during the remainder of this procedure.
(7) If the vehicle is so equipped, remove the two
screws that secure the automatic headlamp light sen-
sor/vehicle theft security system indicator unit to the
instrument panel top pad just outboard of the driver
side defroster outlet. Move the sensor/indicator unit
towards the windshield to keep it out of the way dur-
ing the remainder of this procedure.
(8) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(9) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(10) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(11) Roll the glove box down from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - STANDARD PROCEDURE - GLOVE
BOX ROLL DOWN).
(12) Remove the end cap from the passenger side
lower outboard end of the instrument panel. (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL END CAP - REMOVAL).
(13) Remove the lower right center bezel from the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/IP LOWER RIGHT CENTER BEZEL
- REMOVAL).
(14) Remove the glove box lamp and switch from
the instrument panel. (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - INTERIOR/GLOVE BOX
LAMP/SWITCH - REMOVAL).
23 - 52 INSTRUMENT PANEL SYSTEMWJ
INSTRUMENT PANEL TOP COVER (Continued)

FLOOR CONSOLE
REMOVAL
CAUTION: The ACM should be depowered by dis-
connecting the negative battery cable in any opera-
tion requiring the key to be turned ªONº, while
working in the console area. E.G. console, carpet,
or seat removal or installation; shifter linkage
adjustment or replacement; parking brake cable
replacement or adjustment. Failure to take proper
precautions could result in accidental airbag
deployment and possible personal injury.
(1) Set park brake.
(2) Place transmission shift lever and transfer case
lever in full rearward position.
(3) Remove mat from front bin and remove screws
attaching front of console to floor (Fig. 8).
(4) Remove screws attaching rear bin to console.
(5) Remove rear bin.
(6) Pull rear passenger cupholder outward to
access screws.
(7)
Remove screws attaching rear of console to floor.
(8) Lift the console upward and rearward.
(9) Remove console from vehicle.
INSTALLATION
CAUTION: The ACM should be depowered by dis-
connecting the negative battery cable in any opera-
tion requiring the key to be turned ªONº, while
working in the console area. E.G. console, carpet,
or seat removal or installation; shifter linkage
adjustment or replacement; parking brake cable
replacement or adjustment. Failure to take proper
precautions could result in accidental airbag
deployment and possible personal injury.
(1) Position console in vehicle. Ensure rear passen-
ger HEVAC duct is engaged.
(2) Install screws attaching rear of console to floor.
(3) Position rear bin in console.
(4) Install screws attaching rear bin to console.
(5) Install screws attaching front of console to floor
and place front bin mat in front bin.
(6) Return transmission shift lever and transfer
case lever to original position.
(7) Release park brake.
Fig. 8 Floor Console
1 - REAR BIN
2 - CONSOLE LID
3 - SHIFTER CONSOLE
4 - BRACKET5 - PARKING BRAKE
6 - FRONT PIN
7-MAT
23 - 76 INTERIORWJ

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)