2002 JEEP GRAND CHEROKEE Outlet

(22) Remove the front bin from the floor console.
(Refer to 23 - BODY/INTERIOR/FLOOR CONSOLE -
REMOVAL).
(23) Reach through the front bin opening of the
floor console to access and remove the two screws
that secure the center floor tunnel bracket to the
instrument panel.
(24) Reach through the front bin opening of the
floor console to access and loosen the two nuts that
secure the center floor tunnel bracket to the studs on
the floor panel transmission tunnel.
(25) Slide the center floor tunnel bracket rearward
in the vehicle far enough to disengage the locating
hole in the lower flange of the top pad from the locat-
ing pin on the instrument panel structural duct (Fig.
25).
(26) Remove the instrument panel top pad from
the instrument panel structural duct.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.
If the top pad is being replaced with a new unit, be
certain to transfer or install the panel outlets and
the passenger side trim bezel to the new unit before
it is installed on the instrument panel structural
duct. (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION/AIR OUTLETS - REMOVAL)
and (Refer to 23 - BODY/INSTRUMENT PANEL/IP
TRIM BEZEL - PASSENGER - REMOVAL).
(1) Position the instrument panel top pad over the
instrument panel structural duct and the studs on
the dash panel near the windshield fence line.
(2) Route the instrument panel wire harness take
out for the glove box lamp and switch unit to the
switch mounting hole in the upper glove box opening
reinforcement.
(3) Reach through the front bin opening of the
floor console to engage the locating hole in the lower
flange of the top pad with the locating pin on the
instrument panel structural duct (Fig. 25).
(4) Reach through the front bin opening of the
floor console to slide the center floor tunnel bracket
forward in the vehicle far enough to capture the
lower flange of the top pad between the bracket and
the structural duct.
(5) Reach through the front bin opening of the
floor console to install and tighten the two screws
that secure the center floor tunnel bracket to the
instrument panel. Tighten the screws to 11.8 N´m
(105 in. lbs.).
Fig. 25 Instrument Panel Top Pad Remove/Install
1 - STRUCTURAL DUCT
2 - LOCATING PIN
3 - INSTRUMENT PANEL TOP PAD
4 - LOWER FLANGE
5 - CENTER FLOOR TUNNEL BRACKET
23 - 54 INSTRUMENT PANEL SYSTEMWJ
INSTRUMENT PANEL TOP PAD (Continued)

(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)

INSTRUMENT PANEL CENTER
BEZEL - LOWER
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO MIN-
UTES FOR THE AIRBAG SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Using a trim stick or another suitable wide
flat-bladed tool, gently pry each of the four corners of
the center lower bezel away from the instrument
panel far enough to disengage the four snap clips
from their receptacles (Fig. 27).
(3) Pull the center lower bezel away from the
instrument panel far enough to access the instru-
ment panel wire harness connectors.
(4) Squeeze the mounting legs of the ash receiver
lamp hood and remove it from the rectangular hole
in the ash receiver flame shield.(5) If the vehicle is so equipped, disconnect the
instrument panel wire harness connectors for the two
heated seat switches from the switch connector
receptacles.
(6) Disconnect the instrument panel wire harness
connectors for the cigar lighter and accessory power
outlet from the lighter and outlet connector recepta-
cles.
(7) Remove the center lower bezel from the instru-
ment panel.
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) Position the center lower bezel to the instru-
ment panel.
(2) Reconnect the instrument panel wire harness
connectors for the cigar lighter and the accessory
power outlet to the lighter and outlet connector
receptacles.
(3) If the vehicle is so equipped, reconnect the
instrument panel wire harness connectors for the two
heated seat switches to the switch connector recepta-
cles.
(4) Squeeze the mounting legs of the ash receiver
lamp hood and install them into the rectangular hole
in the ash receiver flame shield.
(5) Align the two lower snap clips on the center
lower bezel with their receptacles in the instrument
panel top pad.
(6) Using hand pressure, press firmly and evenly
on the center lower bezel over each of the lower snap
clip locations until each of the snap clips is fully
engaged in its receptacle.
(7) Align the two upper snap clips on the center
lower bezel with their receptacles in the instrument
panel top pad.
(8) Using hand pressure, press firmly and evenly
on the center lower bezel over each of the upper snap
clip locations until each of the snap clips is fully
engaged in its receptacle.
(9) Reconnect the battery negative cable.
Fig. 27 Instrument Panel Center Lower Bezel
Remove/Install
1 - HEATER AND AIR CONDITIONER CONTROLS
2 - TRIM STICK
3 - CENTER LOWER BEZEL
WJINSTRUMENT PANEL SYSTEM 23 - 57

panel steering column support bracket. (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/JUNCTION
BLOCK - INSTALLATION).
(7) Position the 16-way data link connector to the
instrument panel steering column support bracket.
(8) Install and tighten the two screws that secure
the 16-way data link connector to the instrument
panel steering column support bracket. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(9) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(10) Reconnect the battery negative cable.
INSTRUMENT PANEL TRIM
BEZEL - DRIVER
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) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the edges of the driver
side trim bezel up and away from the instrument
panel far enough to disengage the two snap clips
from their receptacles (Fig. 36).
(3) Remove the driver side trim bezel from the
instrument panel top pad.
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) Position the driver side trim bezel to the
instrument panel top pad.
(2) Align the snap clips on the driver side trim
bezel with the receptacles in the instrument panel
top pad.
(3) Using hand pressure, press firmly and evenly
on the driver side trim bezel over the snap clip loca-
tions until each of the snap clips is fully engaged in
its receptacle.
(4) Reconnect the battery negative cable.
Fig. 36 Instrument Panel Driver Side Trim Bezel
Remove/Install
1 - INSTRUMENT PANEL TOP PAD
2 - DRIVER SIDE TRIM BEZEL
3 - TRIM STICK
4 - PANEL OUTLET
WJINSTRUMENT PANEL SYSTEM 23 - 65
INSTRUMENT PANEL STEERING COLUMN SUPPORT BRACKET (Continued)

POWER OUTLET DOOR
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 center lower bezel from the instru-
ment panel. (Refer to 23 - BODY/INSTRUMENT
PANEL/IP CENTER BEZEL - LOWER - REMOVAL).
(3) With the power outlet door in the open posi-
tion, carefully spread the power outlet door hinge
arms far enough to disengage the pivot pins from the
pivots on the back side of the center lower bezel (Fig.
38).
NOTE: The power outlet door is more easily ser-
viced while in the open position. The illustration
shows the door in the closed position for improved
visibility of the assist spring orientation and anchor
point details.
(4) Disengage the stepped ends of the assist spring
from the anchor holes in the inboard power outlet
door hinge arm and in the side of the ash receiver
housing.
(5) Remove the power outlet door from the instru-
ment panel center lower bezel.
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) Position the power outlet door to the instru-
ment panel center lower bezel.
(2) Engage the stepped ends of the assist spring
with the anchor holes in the inboard power outlet
door hinge arm and in the side of the ash receiver
housing (Fig. 38).
(3) With the power outlet door in the open posi-
tion, carefully spread the power outlet door hinge
arms far enough to engage the pivot pins with the
pivots on the back side of the lower center bezel.
(4) Reinstall the center lower bezel into the instru-
ment panel. (Refer to 23 - BODY/INSTRUMENT
PANEL/IP CENTER BEZEL - LOWER - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
Fig. 38 Instrument Panel Power Outlet Door
Remove/Install
1 - CENTER LOWER BEZEL
2 - ASH RECEIVER FLAME SHIELD
3 - ASH RECEIVER HOUSING
4 - PIVOT PINS
5 - ASSIST SPRING
6 - POWER OUTLET DOOR HINGE ARMS
WJINSTRUMENT PANEL SYSTEM 23 - 67

LIFTGATE OPENING UPPER
TRIM
REMOVAL
The upper liftgate opening trim is held on with
spring clips.
(1) Grasp the rear of the trim piece and pull down
and back to disengage clips (Fig. 12).
(2) Slide the trim piece to the rear to disengage
headliner locating hooks.
INSTALLATION
The liftgate upper opening trim piece is equipped
with headliner locating hooks (Fig. 13).
(1) Align the locating hooks with the slots in the
headliner.
(2) Engage the spring clips and press the liftgate
upper opening trim panel into place.
QUARTER TRIM PANEL
REMOVAL
(1) Move rear seat to cargo position.
(2) If equipped, remove sunshade cover.
(3) Open liftgate.
(4) Remove upper and lower liftgate opening trim
panels (Refer to 23 - BODY/INTERIOR/LIFTGATE
OPENING UPPER TRIM - REMOVAL).
(5) Remove D-pillar upper trim (Refer to 23 -
BODY/INTERIOR/D-PILLAR TRIM - REMOVAL).
(6) Remove storage bin (right side only) (Refer to
23 - BODY/INTERIOR/REAR STORAGE BOX -
REMOVAL).
(7) Remove C-pillar upper trim panel (Refer to 23 -
BODY/INTERIOR/C-PILLAR TRIM - REMOVAL).
(8) Remove mounting screws.
(9) Pull quarter trim panel forward and disengage
connectors for CD player and power outlet, if
equipped.
(10) Pull quarter trim panel extension in the rear
door opening upward.
(11) Remove rear quarter trim panel.
INSTALLATION
(1) Position quarter trim panel, engage connectors
for CD player and power outlet, if equipped, and
align screw holes.
(2) Install quarter trim panel.
(3) Install C-pillar upper trim panel (Refer to 23 -
BODY/INTERIOR/C-PILLAR TRIM - INSTALLA-
TION).
(4) Install storage bin (Refer to 23 - BODY/INTE-
RIOR/REAR STORAGE BOX - INSTALLATION).
(5) Install D-pillar upper trim panel (Refer to 23 -
BODY/INTERIOR/D-PILLAR TRIM - INSTALLA-
TION).
(6) Install upper and lower liftgate opening trim
panels (Refer to 23 - BODY/INTERIOR/LIFTGATE
OPENING UPPER TRIM - INSTALLATION).
(7) If equipped, install sunshade cover.
(8) Install cargo loops.
(9) Move the rear seat to the upright position.
REAR STORAGE BOX
REMOVAL
(1) Open the storage bin lid and remove screws on
each side of the lid hinge.
(2) Pull upward sharply on the bottom of the bin
to disengage hooks.
(3) Raise bin and move inboard to disengage the
quarter trim panel.
Fig. 12 Upper Liftgate Opening Trim
1 - UPPER LIFTGATE OPENING TRIM
Fig. 13 Headliner Locating Hooks
1 - UPPER LIFTGATE OPENING TRIM
2 - HEADLINER
WJINTERIOR 23 - 79

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)