cloudy days and at night it will probably be slightly
warmer. Infrared Three-Zone Temperature Control
provides side-to-side and front-to-rear variation in
comfort temperature settings. The Infrared Three-
Zone Automatic Temperature Control fan provides a
continuously variable air flow rate to meet occupant
comfort requirements.
FRONT CONTROL PANEL
²AUTO HI/LO± This system features two sets of
automatic control logic that allow either a rapid cool-
down rate or a somewhat slower cool-down rate with
less fan noise. HI-AUTO controls the system to reach
its assigned temperature quickly with a higher fan
speed. LO-AUTO controls the system to reach its
assigned temperature somewhat slower with less fan
noise. Both modes will automatically engage auto
recirculation.
²DE-FROST± The front de-frost function is
active when the rear window defogger function is
active or when the defog/defrost mode is selected.
²RECIRC± The RECIRC button will close the
air inlet door. If the system is in auto recirc (indica-
tor being displayed automatically), pressing the man-
ual recirc button will disable the auto recirc function
until one of the auto keys are pressed or the ignition
is cycled. If Auto HI/LO is pressed while manual
recirc is active, manual recirc will be deactivated.
²REAR WINDOW DEFOGGER± Pushing the
button sends a PCI bus message to the Intelligent
Power Module which controls the Rear Window
Defogger and side view mirror (if equipped) circuitry.
The defogger function will be active for 10 minutes
and can be turned off by a switch press. The defogger
will function while the control is in the OFF mode.
²FAN/MODE± The Fan and Mode knobs have
17 manual selectable positions. Manually changing
either of the rotary knobs for mode or fan speed set-
tings makes control of that function alone manual for
as long as the ignition is on. If only one is changed
manually, the other remains under automatic control.
Pressing the HI-AUTO/LO-AUTO rocker switch
restores full automatic control.
²REAR CONTROL± When the Rear System
control knob is moved to the OFF position, there will
be a delay of approximately 1 second before the sys-
tem actually turns off. This delay is to prevent an
undesired blower dropout if the knob is moved
through OFF to the other selections.
²BLOWER DELAY TIMER± The word DELAY
is displayed at start-up to signify that the system is
waiting so that cold air will not be blowing. This tells
the operator that it is unnecessary to turn the sys-
tem off, raise the temperature setting or turn the fan
speed setting down to prevent cold air from blowing.
A countdown in minutes and seconds until the engineis warm enough to begin delivering heat to the pas-
sengers alternates with the DELAY message at 25
second intervals. This countdown is based on actual
measurement of the rate of engine coolant tempera-
ture change. During the delay time, Defrost mode is
selected and the fan operates at a low speed to keep
the windshield fog free.
REAR CONTROL PANEL
Primary control of the rear compartment unit is in
the instrument panel center stack. The rear unit con-
trol knob there allows the driver to turn the rear
unit off, allow control by the intermediate seat occu-
pants by switching to the REAR position, or provide
fully automatic control based on the temperature set-
ting shown on the front control display.
²REAR CONTROL± Selecting automatic control
of the rear unit at the instrument panel, illuminates
a Locked Padlock in the rear control panel display.
Selecting REAR activates the rear control panel and
the Padlock then appears unlocked.
²FAN KNOB± The rear fan control has Off and
AUTO positions and a range of manual speed set-
tings that override the AUTO setting.
²MODE KNOB± The mode control allows inter-
mediate seat occupants to manually override the
automatic mode and select any balance of air flow
between overhead and floor outlets from full over-
head to full floor.
²SET TEMP± The rear set temp control will
operate identical to the front controls. If the front
control rear set temp button is pressed simulta-
neously with the rear control head, then the front
control head press events shall have priority, i.e. if
the front user presses Rear Set Temp down and the
rear user presses Set Temp up, then the rear set
temp will decrease.
DIAGNOSIS AND TESTING - A/C COOL DOWN
TEST
The heater-A/C control module can perform an A/C
cool down test, which is a test performed during the
manufacturing process to confirm that the air condi-
tioning system is performing satisfactorily. This test
can also provide a quick confirmation of air condi-
tioning system performance to the service technician.
If the test is completed satisfactorily, no further ser-
vice is required. If the test is failed, proceed to the
A/C Performance Test to confirm the a/c system is
operating properly, or use a DRBIIItscan tool to
diagnose the A/C system control and distribution sys-
tems. Refer to the appropriate diagnostic informa-
tion.
24 - 4 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)
Performance Temperature and Pressure
Ambient Temperature 21É C
(70É F)27É C
(80É F)32É C
(90É F)38É C
(100É F)43É C
(110É F)
Left Center Panel
Outlet Discharge Air
Temperature1to8ÉC
(34 to 46É F)3to9ÉC
(37 to 49É F)4 to 10ÉC
(39 to 50É F)6to11ÉC
(43 to 52É F)7 to 18É C
(45 to 65É F)
Discharge Pressure
(High Side Service
Port)1034 to 1724
kPa
(150 to 250
psi)1517 to 2275
kPa
(220 to 330
psi)1999 to 2620
kPa
(290 to 380
psi)2068 to 2965
kPa
(300 to 430
psi)2275 to 3421
kPa
(330 to 450 psi)
Suction Pressure (Low
Side Service Port)103 to 207 kPa
(15 to 30 psi)117 to 221 kPa
(17 to 32 psi)138 to 241 kPa
(20 to 35 psi)172 to 269 kPa
(25 to 39 psi)207 to 345 kPa
(30 to 50 psi)
DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST
PRE-DIAGNOSTIC PREPARATIONS
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING FRONT - WARNING - HEATER PLUMB-
ING).
Check the coolant level, drive belt tension, radiator
air flow, and cooling fan operation. Start the engine
and allow it to warm up to normal temperature.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two 16 mm (5/8 inch inside diameter) heater hoses.
With the engine idling at normal running tempera-
ture, set the heater-A/C controls as follows. Temper-
ature control to full Heat, Mode control to Floor,
Blower control to the highest speed setting. Using a
test thermometer, check the air temperature coming
from the center floor outlets and compare this read-
ing to the Temperature Reference table.
TEMPERATURE REFERENCE
AMBIENT
TEMPERATUREMINIMUM FLOOR
OUTLET TEMPERATURE
CELSIUS FAHRENHEIT CELSIUS FAHRENHEIT
15.5É 60É 62.2É 144É
21.1É 70É 63.8É 147É
26.6É 80É 65.5É 150É
32.2É 90É 67.2É 153ÉIf the floor outlet air temperature is insufficient,
check that the cooling system is operating to specifi-
cations. (Refer to 7 - COOLING/ENGINE - DIAGNO-
SIS AND TESTING). Both heater hoses should be
HOT to the touch (the coolant return hose should be
slightly cooler than the supply hose). If the coolant
return hose is much cooler than the supply hose,
locate and repair the engine coolant flow obstruction
in heater system.
POSSIBLE LOCATIONS OR CAUSE OF OBSTRUCTED
COOLANT FLOW
²Pinched or kinked heater hoses.
²Improper heater hose routing.
²Plugged heater hoses or supply and return ports
at cooling system connections.
²Plugged heater core.
²Air locked heater core.
²Restrictor in backwards.
If coolant flow is verified and the heater floor out-
let temperature is insufficient, a mechanical problem
may exist.
POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT HEAT
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend-air door not functioning properly.
TEMPERATURE CONTROL
If heater floor outlet temperature cannot be
adjusted with the heater-A/C control temperature
control lever, one of the following could require ser-
vice:
²Blend-air door binding.
²Faulty blend-air door motor.
²Improper engine coolant temperature.
²Faulty heater-A/C control.
24 - 6 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)
(2) Drain the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(3) Disconnect and isolate the battery negative
cable.
(4) Raise and support the vehicle.
(5) Disconnect the underbody refrigerant line seal-
ing plate from the rear heater-A/C unit evaporator
extension line sealing plate that extends through the
rear floor panel behind the right rear wheel housing
(Fig. 6).
(6) Remove the seals from the liquid line and suc-
tion line fittings and discard.
(7) Install plugs in, or tape over the opened liquid
line and suction line fittings and both ports in the
evaporator extension line sealing plate.
(8) Remove the three nuts that secure the rear
heater-A/C unit mounting studs to the rear floor
panel behind the right rear wheel housing (Fig. 7).
(9) Lower the vehicle.
(10) Remove the right quarter trim panel and
right D-pillar trim panel from the quarter inner
panel. (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - REMOVAL).
(11) Remove the rear A/C distribution duct from
the rear heater-A/C unit and the rear roof duct.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION - REAR/AUXILIARY A/C DISTRI-
BUTION DUCT - REMOVAL).
(12) Disconnect the body wire harness connector
for the rear heater-A/C unit housing from the rear
HVAC wire harness connector located near the
expansion valve at the back of the unit.
(13) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.(14) Remove the two screws that secure the bottom
of the quarter trim panel attaching bracket to the
rear heater-A/C unit housing.
(15) Remove the rear heater distribution duct from
the right quarter inner panel. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION -
REAR/REAR HEATER DISTRIBUTION DUCT -
REMOVAL).
(16) Take the proper precautions to protect the
carpeting below the rear heater core from spilled
engine coolant and have absorbent toweling readily
available to clean up any spills.
(17) Disconnect the heater hoses at the rear heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE - REMOV-
AL).
(18) Install plugs in, or tape over the opened
heater core fittings and both heater hoses.
(19) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
(20) Remove the screw that secures the back of the
rear heater-A/C unit housing to the right D-pillar
(Fig. 8).
(21) Remove the screw that secures the front of
the rear heater-A/C unit housing to the right quarter
inner panel.
(22) Lift the rear heater-A/C unit housing up far
enough for the lower mounting studs and the evapo-
rator extension lines to clear the mounting holes in
the rear floor panel.
(23) Remove the rear heater-A/C unit housing from
the vehicle.
(24) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
Fig. 6 Refrigerant Lines
1 - UNDERBODY REFRIGERANT LINE SEALING PLATE
Fig. 7 Rear Heater-A/C Unit Mounting Studs
1 - REAR HEATER-A/C UNIT MOUNTING STUDS
RSDISTRIBUTION - REAR24-59
REAR HEATER-A/C HOUSING (Continued)
INSTALLATION
NOTE: If the rear heater core or the rear heater-A/C
housing have been removed from the vehicle for
service, the rear heater core may be pre-filled with
the proper engine coolant mixture prior to recon-
necting the heater hoses to the heater core hose fit-
tings. (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - REAR/HEATER CORE - STANDARD
PROCEDURE - HEATER CORE FILLING).
(1) Position the rear heater-A/C unit housing into
the vehicle with the evaporator extension line sealing
plate inserted into the rectangular hole in the rear
floor panel behind the right rear wheel house.
(2) Align the rear heater-A/C unit housing lower
mounting studs with the mounting holes in the rear
floor panel and lower the unit to the floor (Fig. 8).(3) Install and tighten the screw that secures the
front of the rear heater-A/C unit housing to the right
quarter inner panel. Tighten the screw to 11 N´m (97
in. lbs.).
(4) Install and tighten the screw that secures the
back of the rear heater-A/C unit housing to the right
D-pillar. Tighten the screw to 11 N´m (97 in. lbs.).
(5) Remove the plugs or tape from both heater core
fittings and both heater hoses.
(6) Reconnect the heater hoses to the rear heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE - INSTAL-
LATION).
(7) Reinstall the rear heater distribution duct onto
the right quarter inner panel. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION -
REAR/REAR HEATER DISTRIBUTION DUCT -
INSTALLATION).
Fig. 8 Rear Heater-A/C Housing
1 - U-NUT (3)
2 - REAR HEATER-A/C HOUSING
3 - SCREW (3)
4 - EXPANSION VALVE
5 - STUD (3)6 - HEATER LINES
7 - NUT (5)
8 - STUD (2)
24 - 60 DISTRIBUTION - REARRS
REAR HEATER-A/C HOUSING (Continued)
PLUMBING - FRONT
TABLE OF CONTENTS
page page
PLUMBING - FRONT
WARNING..............................62
CAUTION...............................63
COMPRESSOR
DESCRIPTION...........................64
OPERATION.............................65
DIAGNOSIS AND TESTING.................65
COMPRESSOR NOISE DIAGNOSIS.........65
REMOVAL..............................65
INSTALLATION...........................66
CONDENSER
DESCRIPTION...........................67
OPERATION.............................67
REMOVAL..............................68
INSTALLATION...........................69
DISCHARGE LINE
REMOVAL..............................70
INSTALLATION...........................70
EVAPORATOR
DESCRIPTION...........................71
OPERATION.............................71
REMOVAL..............................71
INSTALLATION...........................73
EXPANSION VALVE
DESCRIPTION...........................74
OPERATION.............................74
DIAGNOSIS AND TESTING.................74
EXPANSION VALVE.....................74
REMOVAL..............................75
INSTALLATION...........................75
HEATER CORE
DESCRIPTION...........................76
OPERATION.............................76
REMOVAL..............................76INSTALLATION...........................79
HEATER HOSE
REMOVAL..............................80
INSTALLATION...........................82
LIQUID LINE
REMOVAL..............................82
INSTALLATION...........................84
RECEIVER/DRIER
DESCRIPTION...........................85
OPERATION.............................86
REMOVAL..............................86
INSTALLATION...........................86
REFRIGERANT
DESCRIPTION...........................87
OPERATION.............................87
DIAGNOSIS AND TESTING.................87
REFRIGERANT SYSTEM CHARGE LEVEL....87
REFRIGERANT SYSTEM LEAKS...........89
STANDARD PROCEDURE..................89
SERVICE EQUIPMENT...................89
REFRIGERANT SYSTEM CHARGE.........90
REFRIGERANT SYSTEM EVACUATE........91
REFRIGERANT RECOVERY...............91
REFRIGERANT OIL
DESCRIPTION...........................91
OPERATION.............................92
STANDARD PROCEDURE..................92
REFRIGERANT OIL LEVEL................92
SUCTION LINE
REMOVAL..............................92
INSTALLATION...........................93
SERVICE PORTS
REMOVAL..............................94
INSTALLATION...........................95
PLUMBING - FRONT
WARNING
WARNING: THE ENGINE COOLING SYSTEM IS
DESIGNED TO DEVELOP INTERNAL PRESSURES
OF 97 TO 123 KILOPASCALS (14 TO 18 POUNDS
PER SQUARE INCH). DO NOT REMOVE OR
LOOSEN THE COOLANT PRESSURE CAP, CYLIN-
DER BLOCK DRAIN PLUGS, RADIATOR DRAIN,RADIATOR HOSES, HEATER HOSES, OR HOSE
CLAMPS WHILE THE SYSTEM IS HOT AND UNDER
PRESSURE. FAILURE TO OBSERVE THIS WARNING
CAN RESULT IN SERIOUS BURNS FROM THE
HEATED ENGINE COOLANT. ALLOW THE VEHICLE
TO COOL FOR A MINIMUM OF 15 MINUTES
BEFORE OPENING THE COOLING SYSTEM FOR
SERVICE.
24 - 62 PLUMBING - FRONTRS
WARNING: THE ENGINE COOLING SYSTEM CON-
TAINS ANTIFREEZE. ANTIFREEZE IS AN ETHYLENE
GLYCOL BASED COOLANT AND IS HARMFUL IF
SWALLOWED OR IF THE VAPORS ARE INHALED. IF
SWALLOWED, DRINK TWO GLASSES OF WATER
AND INDUCE VOMITING. IF VAPORS ARE INHALED,
MOVE TO AN AREA FOR FRESH AIR. SEEK MEDI-
CAL ATTENTION IMMEDIATELY. DO NOT STORE IN
OPEN OR UNMARKED CONTAINERS. WASH SKIN
AND CLOTHING THOROUGHLY AFTER COMING IN
CONTACT WITH ETHYLENE GLYCOL. KEEP OUT
OF REACH OF CHILDREN.
WARNING: DISPOSE OF ETHYLENE GLYCOL
BASED COOLANT PROPERLY. CONTACT YOUR
DEALER OR A LOCAL GOVERNMENT AGENCY FOR
THE LOCATION OF AN APPROVED ETHYLENE GLY-
COL COLLECTION AND/OR RECYCLING CENTER IN
YOUR AREA.
WARNING - A/C PLUMBING
WARNING: THE AIR CONDITIONING SYSTEM CON-
TAINS REFRIGERANT UNDER HIGH PRESSURE.
SEVERE PERSONAL INJURY MAY RESULT FROM
IMPROPER SERVICE PROCEDURES. REPAIRS
SHOULD ONLY BE PERFORMED BY QUALIFIED
SERVICE PERSONNEL.
WARNING: AVOID BREATHING THE REFRIGERANT
AND REFRIGERANT OIL VAPOR OR MIST. EXPO-
SURE MAY IRRITATE THE EYES, NOSE, AND/OR
THROAT. WEAR EYE PROTECTION WHEN SERVIC-
ING THE AIR CONDITIONING REFRIGERANT SYS-
TEM. SERIOUS EYE INJURY CAN RESULT FROM
DIRECT CONTACT WITH THE REFRIGERANT. IF
EYE CONTACT OCCURS, SEEK MEDICAL ATTEN-
TION IMMEDIATELY.
WARNING: DO NOT EXPOSE THE REFRIGERANT
TO OPEN FLAME. POISONOUS GAS IS CREATED
WHEN REFRIGERANT IS BURNED. AN ELEC-
TRONIC LEAK DETECTOR IS RECOMMENDED.
WARNING: IF ACCIDENTAL SYSTEM DISCHARGE
OCCURS, VENTILATE THE WORK AREA BEFORE
RESUMING SERVICE. LARGE AMOUNTS OF
REFRIGERANT RELEASED IN A CLOSED WORK
AREA WILL DISPLACE THE OXYGEN AND CAUSE
SUFFOCATION.
WARNING: THE EVAPORATION RATE OF R-134a
REFRIGERANT AT AVERAGE TEMPERATURE ANDALTITUDE IS EXTREMELY HIGH. AS A RESULT,
ANYTHING THAT COMES IN CONTACT WITH THE
REFRIGERANT WILL FREEZE. ALWAYS PROTECT
THE SKIN OR DELICATE OBJECTS FROM DIRECT
CONTACT WITH THE REFRIGERANT.
WARNING: THE R-134a SERVICE EQUIPMENT OR
THE VEHICLE REFRIGERANT SYSTEM SHOULD
NOT BE PRESSURE TESTED OR LEAK TESTED
WITH COMPRESSED AIR. SOME MIXTURES OF AIR
AND R-134a HAVE BEEN SHOWN TO BE COMBUS-
TIBLE AT ELEVATED PRESSURES. THESE MIX-
TURES ARE POTENTIALLY DANGEROUS, AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
CAUTION - A/C PLUMBING
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with the service equipment being used.
CAUTION: Never add R-12 to a refrigerant system
designed to use R-134a. Damage to the system will
result.
CAUTION: R-12 refrigerant oil must not be mixed
with R-134a refrigerant oil. They are not compatible.
CAUTION: Do not use R-12 equipment or parts on
the R-134a system. Damage to the system will
result. All parts, tools, and equipment must be
designed for R-134a refrigerant.
CAUTION: Do not discharge refrigerant into the
atmosphere. Use an R-134a refrigerant recovery/re-
cycling device that meets SAE Standard J2210.
CAUTION: The refrigerant must be recovered com-
pletely from the system before opening any fitting
or connection. Open the fittings with caution, even
after the system has been discharged. If any pres-
sure is noticed as a fitting is loosened, tighten the
fitting and recover the refrigerant from the system
again.
CAUTION: The refrigerant system must always be
evacuated before charging.
RSPLUMBING - FRONT24-63
PLUMBING - FRONT (Continued)
connector receptacle on the top of the expansion
valve.
(7) Remove the tape or plugs from the front liquid
line rear section and suction line fittings for the
expansion valve and both ports on the front of the
expansion valve.
(8) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the front liquid
line rear section and suction line fittings for the
expansion valve.
(9) Reconnect the liquid line and suction line fit-
tings to the expansion valve.
(10) Install and tighten the nut that secures the
suction line and liquid line fittings to the stud on the
expansion valve. Tighten the nut to 23 N´m (17 ft.
lbs.).
(11) Remove the tape or plugs from the liquid line
rear section fitting for the filter-drier and the filter-
drier outlet port.
(12) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(13) Reconnect the liquid line fitting to the filter-
drier outlet port on the top of the filter-drier.
(14) Install and tighten the screw that secures the
liquid line fitting to the filter-drier. Tighten the screw
to 2 N´m (18 in. lbs.).
(15) Reconnect the headlamp and dash wire har-
ness connector for the A/C pressure transducer to the
transducer on the front liquid line rear section.
(16) Reconnect the drain tube to the wiper module
drain on the right side of the engine compartment.
(17) Reinstall the air cleaner housing into the
right side of the engine compartment.
(18) Reconnect the battery negative cable.
(19) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(20) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
HEATER CORE
DESCRIPTION
The heater core is located in the distribution hous-
ing of the heater-A/C unit, under the instrument
panel. It is a heat exchanger made of rows of tubes
and fins. One end of the core is fitted with a molded
plastic tank that includes integral heater core inlet
and outlet ports. The removable heater core tubes
are held in place these ports by a sealing plate
secured with a screw to the heater core tank. This
removable heater core tube arrangement allows theheater core to be serviced without removing the heat-
er-A/C unit housing from the vehicle. The heater core
cannot be repaired and, if faulty or damaged, it must
be replaced.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend air door
allows control of the heater output air temperature
by controlling how much of the air flowing through
the heater-A/C unit housing is directed through the
heater core.
REMOVAL- HEATER CORE EXTENSION TUBES
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING FRONT - WARNING - HEATER PLUMB-
ING).
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) Drain the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Disconnect and isolate the battery negative
cable.
(3) Disconnect the heater hoses from the heater
hose tubes. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/HEATER HOSE -
REMOVAL).
(4) Remove the silencer from beneath the driver
side end of the instrument panel. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL SILENCER - REMOVAL).
24 - 76 PLUMBING - FRONTRS
EXPANSION VALVE (Continued)
(5) Remove the three screws that secure the heater
core shield to the left end of the HVAC distribution
housing (Fig. 15).
(6) Pull the heater core shield rearward far enough
to disengage the two location tabs that position the
front of the shield to the receptacles in the two lower
finger formations of the evaporator housing near the
dash panel.
(7) Remove the heater core shield from the distri-
bution housing.
(8) Take the proper precautions to protect the car-
peting below the heater core from spilled engine cool-
ant and have absorbent toweling readily available to
clean up any spills.
(9) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 16).
(10) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(11) Install plugs in, or tape over the opened
heater core tube fittings and both heater core ports.
(12) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
(13) Pull both heater core tubes simultaneously
slightly away from the distribution housing and rear-
ward far enough to disengage the engine compart-
ment ends of the tubes from the dash panel seal.
(14) Remove the heater core tubes and sealing
plate as a unit from beneath the instrument panel.
(15) Use absorbent toweling to clean up any
engine coolant spills from the preceding operation.
REMOVAL - HEATER CORE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING FRONT - WARNING - HEATER PLUMB-
ING).
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) Drain the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM DRAIN).
(2) Disconnect and isolate the battery negative
cable.
Fig. 15 Heater Core Shield
1 - HEATER/ AIR CONDITIONER HOUSING
2 - HEATER CORE SHIELD
3 - DISTRIBUTION HOUSING
4 - SCREWS (3)
5 - LOCATION TABS (2)
Fig. 16 Heater Core Tubes
1 - SEAL
2 - HEATER CORE TUBES
3 - SCREW
4 - HEATER CORE
5 - DISTRIBUTION HOUSING
6 - SEALING PLATE
RSPLUMBING - FRONT24-77
HEATER CORE (Continued)