
POSSIBLE LOCATIONS OR CAUSE OF
OBSTRUCTED COOLANT FLOW
(1) Pinched or kinked heater hoses.
(2) Improper heater hose routing.
(3) Plugged heater hoses or supply and return
ports at cooling system connections, refer to Group 7,
Cooling System.
(4) Plugged heater core.
(5) Air locked heater core.
(6) If coolant flow is verified and outlet tempera-
ture is insufficient, a mechanical problem may exist.
POSSIBLE LOCATION OR CAUSE OF INSUFFICIENT
HEAT
(1) Obstructed cowl air intake.
(2) Obstructed heater system outlets.
(3) Blend-air door not functioning properly.
TEMPERATURE CONTROL
If temperature cannot be adjusted with the TEMP
lever on the control panel, the following could require
service:
(1) Blend-air door binding.
(2) Faulty blend-air door cable.
(3) Improper engine coolant temperature.
(4) Faulty Instrument Panel Control.
LOW PRESSURE CUT OFF SWITCH
The work area must not be below 21ÉC (70ÉF) to
test the compressor clutch circuit.
(1) With gear selector in park or neutral and park
brake set, start engine and allow to idle.
(2) Raise hood and disconnect low pressure cut off
switch connector boot.
(3) Using a suitable jumper wire, jump across the
terminals inside wire connector boot.
(4) If the compressor clutch does not engage, the
cycling clutch switch, wiring, relay, or fuse can be
defective. Refer to Group 8W, Wiring Diagrams.
(5) If clutch engages, connect manifold gauge set.
Read low pressure gauge. At pressure above 97 kPa
(14 psi) and above, low pressure out off switch will
complete the clutch circuit. If the low pressure gauge
reads below 140 kPa (20 psi), the system is low on
refrigerant charge or empty due to a leak. Refer to
Service Procedures, System Leak Checking in this
section.
(6) Install connector boot on switch and repeat
Step 3. If the clutch does not engage, replace the low
pressure cut off switch.
SYSTEM CHARGE LEVEL TEST
The procedure below should be used to check
and/or fill the refrigerant charge in the air condition-
ing system.
WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. MIXTURE
OF AIR and R-134a CAN BE COMBUSTIBLE AT ELE-
VATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROP-
ERTY DAMAGE.
NOTE: The maximum amount of R-134a refrigerant
that the air conditioning system holds is 765 grams
(27 oz. or 1.69 lbs.)
It is recommended to use the gauges or reclaim/re-
cycle equipment.
(1) Use a manifold gauge and check the liquid line
pressure.
(2) Attach a clamp-on thermocouple (P. S. E.
66-324-0014 or 80PK-1A) or equivalent to the liquid
line near the filter/drier.
(3) The vehicle must be in the following modes:
²Automatic transaxle in park or manual tran-
saxle in neutral.
²Engine at idle
²A/C controls set to outside air
²Panel mode
²A/C ON full cool
²Blower motor ON high speed
²Vehicle windows closed
(4) Operate system for a couple of minutes to allow
the system to stabilize.
(5) Observe filter/drier pressure and Liquid line
temperature. Using the Charge Determination Chart
(Fig. 14) determine where the system is currently
operating. If the system is not in the proper range,
reclaim all the refrigerant and recharge per A/C
label.
24 - 14 HEATING AND AIR CONDITIONINGPL
DIAGNOSIS AND TESTING (Continued)

HEATER-A/C VACUUM SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO FORCED AIR IN
HEAT POSITION1. Vacuum line pinched or
leaking.
2. Faulty heat defroster or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necassary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
PANEL POSITION1. Vacuum line pinched or
leaking.
2. Faulty mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuator and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
NO FORCED AIR IN
DEFROST POSITION1. Vacuum line pinched or
leaking.
2. Faulty heat, defroster, or
mode door.
3. Faulty selector switch.
4. Vacuum check valve.1. Locate and repair vacuum leak or pinched line.
2. Test actuators and door operation. Repair as
necessary.
3. Test selector switch and replace if necessary.
4. Test check valve and replace if necessary.
ONE-WAY CHECK VALVE
(1) Disconnect the heater-A/C vacuum supply
(Black) tube in the engine compartment. This tube
passes through an opening in the dash panel.
(2) Remove the one-way vacuum check valve. The
valve is located on the (Black) vacuum supply hose at
the brake power booster.
(3) Connect the test set vacuum supply hose to the
heater side of the valve. When connected to this side
of the check valve, no vacuum should pass and the
test set gauge should return to the 27 kPa (8 in. Hg.)
setting. If OK, go to step Step 4. If not OK, replace
the faulty valve.
(4) Connect the test set vacuum supply hose to the
engine vacuum side of the valve. When connected to
this side of the check valve, vacuum should flow
through the valve without restriction. If not OK,
replace the faulty valve.
HEATER-A/C CONTROLS
The operation of the Circulation door can be
viewed by removing the blower motor and looking up
into the unit inlet. See Blower Motor Wheel and
Assembly removal and installation in this section for
service procedures.
(1) Connect the test set vacuum probe to the heat-
er-A/C vacuum supply (Black) hose in the engine
compartment. Position the test set gauge so that it
can be viewed from the passenger compartment.
(2) Start with the Mode control in the Panel posi-
tion and the Circulation control in the Outside-air
position.
(3) Move the Circulation control to the Recircula-
tion position (the Circulation door should move intothe Recirculation position). After a short pause move
the Mode control to the Defrost position (the Circula-
tion door should move to the Outside-air position).
The test gauge should return to the calibrated set-
ting of 27 kPa (8 in. Hg.) after each selection is
made. If the gauge cannot achieve the calibrated set-
ting, the vacuum circuit or a component has a leak.
(4) If the gauge achieves the calibrated setting but
the door does not move, there is either a pinched vac-
uum line or a failed actuator.
LOCATING VACUUM LEAKS
(1) Connect the test vacuum probe to the vehicles
(Black) supply hose. Position the vacuum test gauge
so it can be viewed from the passenger compartment.
(2) Place the Mode in the Panel position and the
Circulation control in the Recirculation position.
(3) Remove the center instrument panel bezel.
(4) Remove the center vent duct.
(5) Remove and block the Supply (Black) vacuum
line at the control. The test gauge should return to
the calibrated setting of 27 kPa (8 in. Hg). If not,
there is a leak in the Supply line.
(6) If there is no leak in the Supply line, reconnect
it to the Control and remove the Actuator Feed (Red)
line from the Control. Block the vacuum connection
on the Control from where the line was removed. The
test gauge should return to the calibrated setting of
27 kPa (8 in. Hg.). If not, there is a leak in the Con-
trol.
(7) If there is no leak in the Supply line or the
Control, reconnect the Actuator Feed (Red) line to the
control. Remove and block the Actuator Feed (Red)
line at the Actuator. The actuator vacuum port is
accessible behind and above the Glove Box. The test
24 - 16 HEATING AND AIR CONDITIONINGPL
DIAGNOSIS AND TESTING (Continued)

gauge should return to the calibrated setting of 27
kPa (8 in. Hg.). If not there is a leak in the Actuator
Feed line.
(8) If there is no leak in the Supply line, Control,
or the Actuator Feed line, the leak must be in the
Actuator itself. Connect the Vacuum hose from the
Vacuum Test Gauge directly to the Actuator to verify
the leak.
LOCATING PINCHED VACUUM LINES
The operation of the Circulation door can be
viewed by removing the blower motor and looking up
into the unit inlet. See Blower Motor Wheel and
Assembly removal and installation in this section for
service procedures.
(1) Connect the test vacuum probe to the vehicles
(Black) supply hose. Position the vacuum test gauge
so it can be viewed from the passenger compartment.
(2) Place the Mode in the Panel position and the
Circulation control in the Recirculation position.
(3) Remove the center instrument panel bezel.
(4) Remove the center vent duct.
(5) Remove the Supply (Black) vacuum line at the
control. The test gauge should drop indicating free
flow through the Supply line. If not, there is a block-
age in the Supply line.
(6) If there is no blockage in the Supply line,
reconnect it to the Control. Remove the Actuator
Feed (Red) line from the Control. The test gauge
should drop indicating free flow through the Supply
line and Control. If not the vacuum switches on the
Control are not functioning.
(7) If there is no blockage in the Supply line or the
Control, reconnect the Actuator Feed (Red) line to the
control. Remove the Actuator Feed (Red) line at the
Actuator. The Actuator vacuum port is accessible
behind and above the Glove Box. The test gauge
should drop indicating free flow through the supply
line, Control, and the Actuator Feed line. If not,
there is a blockage in the Actuator Feed line.
(8) If there is no blockage in the Supply line, Con-
trol, or the Actuator Feed line, the Actuator must
have failed. Connect the Vacuum hose from the Vac-
uum Test Gauge directly to the Actuator to verify the
Actuator has failed.
SERVICE PROCEDURES
CHARGING A/C SYSTEM
PARTIAL CHARGE
This vehicle does not have a sight glass. It is not
possible to determine the amount of (R-134a) charge
in the system. Therefore it is necessary to completely
evacuate and recover the system, and then recharge
the system fully.
EVACUATION
Before adding refrigerant, all air must be evacu-
ated from the system.
²Connect a manifold gauge set to the A/C service
ports (Fig. 16).
²Use a vacuum pump or charging station and
evacuate system to 95 kPa (28 inches Hg) for 30 min-
utes.
²Go to Charging A/C System below.
CHARGING A/C SYSTEM
The procedure below should be used to fill the
refrigerant charge in the air conditioning system.
This A/C system does not have or use a sight glass to
check or charge the system.
WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS IN THIS GROUP BEFORE CHARGING
THE REFRIGERANT SYSTEM.
AVOID BREATHING A/C REFRIGERANT AND
LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
R-134a SERVICE EQUIPMENT OR VEHICLE A/C
SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. MIXTURE
OF AIR and R-134a CAN BE COMBUSTIBLE AT ELE-
VATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROP-
ERTY DAMAGE.
Fig. 16 A/C Service Ports
1 ± A/C SERVICE PORTS
2 ± FILTER/DRIER
PLHEATING AND AIR CONDITIONING 24 - 17
DIAGNOSIS AND TESTING (Continued)

CAUTION: Do not overcharge refrigerant system,
as excessive compressor head pressure can cause
noise and system failure.
After the system has been tested for leaks and
evacuated, a refrigerant (R-134a) charge can be
injected into the system.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) If using a separate vacuum pump close all
valves before disconnecting pump. Connect manifold
gauge set to the A/C service ports (Fig. 16).
NOTE: The air conditioning system in this vehicle
holds (27 oz. or 1.69 lbs.) of R-134a refrigerant.
(2) Measure refrigerant (refer to capacities). Refer
to the instructions provided with the equipment
being used.
(3) Verify engine is shut off. Open the suction and
discharge valves. Open the charge valve to allow the
refrigerant to flow into the system. When the trans-
fer of refrigerant has stopped, close the suction and
discharge valve.
(4) If all of the charge did not transfer from the
dispensing device, put vehicle controls into the fol-
lowing mode:
²Automatic transaxle in park or manual tran-
saxle in neutral
²Engine idling at 700 rpm
²A/C control set in 100 percent outside air
²Panel mode
²Blower motor ON high speed
²Vehicle windows closed
If the A/C compressor does not engage, test the
compressor clutch control circuit and correct any fail-
ure. Refer to Group 8W, Wiring Diagrams.
(5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system perfor-
mance.
(7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
EVACUATING REFRIGERANT SYSTEM
NOTE: Special effort must be used to prevent mois-
ture from entering the A/C system oil. Moisture in
the oil is very difficult to remove and will cause a
reliability problem with the compressor.If a compressor designed to use R-134a refrigerant
is left open to the atmosphere for an extended period
of time. It is recommended that the refrigerant oil be
drained and replaced with new oil or a new compres-
sor be used. This will eliminate the possibility of con-
taminating the refrigerant system.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be filled. Moisture and air mixed with the refrig-
erant will raise the compressor head pressure above
acceptable operating levels. This will reduce the per-
formance of the air conditioner and damage the com-
pressor. Moisture will boil at near room temperature
when exposed to vacuum. To evacuate the refrigerant
system:
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a suitable charging station, refrigerant
recovery machine, and a manifold gauge set with
vacuum pump (Fig. 17).
(2) Open the suction and discharge valves and
start the vacuum pump. The vacuum pump should
run a minimum of 45 minutes prior to charge to
eliminate all moisture in system. When the suction
gauge reads -88 kPa (- 26 in. Hg) vacuum or greater
for 45 minutes, close all valves and turn off vacuum
pump. If the system fails to reach specified vacuum,
the refrigerant system likely has a leak that must be
corrected. If the refrigerant system maintains speci-
fied vacuum for at least 30 minutes, start the vac-
uum pump, open the suction and discharge valves.
Fig. 17 Refrigerant Recovery Machine Hookup -
Typical
1 ± LOW SIDE CONNECTOR
2 ± HIGH SIDE CONNECTOR
3 ± TO MANIFOLD SET
24 - 18 HEATING AND AIR CONDITIONINGPL
SERVICE PROCEDURES (Continued)

REMOVAL
(1) Disconnect liquid line from filter/drier.
(2) Disconnect liquid line on suction line assembly
from filter/drier.
(3) Pull filter/drier out of rubber grommet.
INSTALLATION
For installation, reverse the above procedures.
A/C SERVICE PORT VALVE CORES
REMOVAL
(1) Remove the valve caps (Fig. 4).
(2) Using a R-134a refrigerant recovery machine,
Remove the refrigerant from A/C system.
(3) Using a standard valve core tool, remove the
valve core.Be careful to prevent any dirt/debris
from entering the valve core opening or getting
on the replacement valve core.
INSTALLATION
(1) When assembling the new valve core into the
port, the core should be oiled with clean ND8 PAG
compressor oil.
CAUTION: A valve that is not fully seated can lead
to damage to the valve during evacuation and
charge. This can result in system refrigerant dis-
charge while uncoupling the charge adapters.
(2) Install valve core into port.
(3) Evacuate and charge the A/C system.
(4) Install the valve caps.
BLOWER MOTOR AND WHEEL ASSEMBLY
The blower motor is located on the bottom right
side of the unit housing. The blower motor can be
removed from the vehicle without having to remove
the unit housing assembly.
WITH AIR CONDITIONING
REMOVAL
(1) Remove right side scuff plate.
(2) Pull back carpet.
(3) Disconnect blower motor wiring connector.
(4) Remove blower motor retaining screws, and
lower blower motor assembly from unit housing (Fig.
20).
INSTALLATION
For installation, reverse the above procedures.
WITHOUT AIR CONDITIONING
REMOVAL
(1) Disconnect blower motor wiring connector.
(2) Grasp the blower motor while pulling down
tab. Turn approximately 1/8 turn counterclockwise
and remove blower motor assembly from unit hous-
ing (Fig. 21).
INSTALLATION
For installation, reverse the above procedures.
Fig. 20 Blower Motor Retaining Screws
1 ± BLOWER MOTOR
2 ± BLOWER MOTOR RETAINING SCREWS
3 ± BLOWER MOTOR WIRING
Fig. 21 Blower Motor Removal
1 ± BLOWER MODULE
2 ± BLOWER MOTOR
PLHEATING AND AIR CONDITIONING 24 - 21
REMOVAL AND INSTALLATION (Continued)

BLOWER MOTOR RESISTOR
CAUTION: Stay clear of the blower motor and resis-
tor block (Hot). Do not operate the blower motor
with the resistor block removed.
REMOVAL
(1) Remove windshield wipers.
(2) Remove cowl top screen.
(3) Disconnect the resistor block wiring connector
(Fig. 22).
(4) Remove/unsnap resistor block from vehicle.
INSTALLATION
For installation, reverse the above procedures.
BLOWER MOTOR WHEEL
The blower motor wheel is only serviced with the
blower motor. The wheel and the motor are balanced
as an assembly. If the blower motor wheel requires
replacement, the blower motor must also be replaced.
Refer to blower motor for replacement procedure.
COMPRESSOR
CAUTION: Add only new lubricant when system
requires additional lubricant. Do not use old
reclaimed lubricant.
REMOVAL
The A/C compressor may be unbolted and reposi-
tioned without discharging the refrigerant system.
Discharging is not necessary if removing the com-
pressor clutch/coil assembly, engine, cylinder head, or
alternator.
WARNING: REFRIGERANT PRESSURES REMAIN
HIGH EVEN THOUGH THE ENGINE MAY BE
TURNED OFF. DO NOT TWIST OR KINK THE
REFRIGERANT LINES WHEN REMOVING A FULLY
CHARGED COMPRESSOR. SAFETY GLASSES
MUST BE WORN.
(1) Disconnect battery negative cable.
(2) Loosen and remove drive belts, refer to Group
7, Engine Cooling.
(3) Using a R-134a refrigerant recovery machine,
remove the refrigerant from A/C system. If the com-
pressor is being replaced.
(4) Disconnect compressor clutch wire lead.
(5) Remove refrigerant lines from compressor, if
necessary (Fig. 23).
(6) If system is left open place plug/cap over open
lines.
(7) Remove compressor attaching bolts (Fig. 24).
Fig. 22 Blower Motor Resistor Block
1 ± RESISTOR BLOCK
2 ± ELECTRICAL CONNECTOR
Fig. 23 A/C Compressor Lines
1 ± CONDENSER LIQUID LINE
2 ± SUCTION LINE
3 ± COMPRESSOR MANIFOLD SCREWS
4 ± COMPRESSOR
5 ± DISCHARGE LINE
24 - 22 HEATING AND AIR CONDITIONINGPL
REMOVAL AND INSTALLATION (Continued)

diameter, and make a new hole. Make the hole 1/4
inch above, or below the original hole in the evapora-
tor core.(3) Insert new probe into hole between evaporator
fins.
(4) Reinstall rubber grommet into evaporator
probe access hole.
EXPANSION VALVE
WARNING: THE REFRIGERATION SYSTEM MUST
BE COMPLETELY EMPTY BEFORE PROCEEDING
WITH THIS OPERATION.
Fig. 33 Lower HVAC Housing
1 ± EVAPORATOR AND CONNECTION
2 ± FOAM SEALS
3 ± HEATER CORE AND TUBES
4 ± HVAC HOUSING LOWER CASE
5 ± HOUSING MOUNTING STUDS
6 ± HOUSING DRAIN
7 ± WIRING
8 ± BLOWER MOTOR AND WHEEL
Fig. 34 Case Separation - Typical
1 ± CASE HALVES
2 ± EVAPORATOR
3 ± BLOWER WHEEL
Fig. 35 Evaporator Removal - Typical
1 ± EVAPORATOR
2 ± BLOWER WHEEL
Fig. 36 Evaporator Probe Location - Typical
1 ± EVAPORATOR PROBE WIRING CONNECTOR
2 ± EVAPORATOR PROBE RUBBER GROMMET
3 ± EVAPORATOR/BLOWER MODULE
PLHEATING AND AIR CONDITIONING 24 - 27
REMOVAL AND INSTALLATION (Continued)

INSTALLATION
For installation, reverse the above procedures.
DISASSEMBLY AND ASSEMBLY
HEATER-A/C HOUSING
Use this procedure if any or all of the following
items require service:
²Heater core
²Evaporator
²HVAC housing
The HVAC housing must be removed from the
vehicle before beginning with this procedure. Refer to
Unit Housing in this section for removal procedure.
DISASSEMBLY
(1) Separate the air distribution outlet foam seals
at the case parting line (Fig. 52).
(2) Remove the evaporator lines foam seal, and
heater core tubes foam seal from the unit (Fig. 53).
(3) Remove the retaining clips and screws that
hold the upper and lower housings together.
(4) Separate the two halves of the housing.
(5) Lift the heater core/evaporator out of the case.
ASSEMBLY
To reassemble, reverse the above procedures.
ADJUSTMENTS
MODE CONTROL CABLE
(1) Engage cable to actuator arm lever on mode
door and attach to housing (Fig. 47).
(2) Attach other end of cable to instrument panel
control (Fig. 43).
(3) Turn the mode knob completely counterclock-
wise.
(4) While holding the knob in the counterclockwise
position, pull on the gray casing of the mode cable.
This will take up any free play in the cable and index
the mode door to the mode knob.
(5) Then snap the cable hold down clip into posi-
tion.
TEMPERATURE CONTROL CABLE
(1) Engage cable to actuator arm on temperature
door and attach to housing (Fig. 47).
(2) Attach other end of cable to instrument panel
control (Fig. 43).
(3) Turn the temperature knob completely counter-
clockwise.
Fig. 52 HVAC Housing Air Distribution Foam Seals
1 ± AIR DISTRIBUTION
2 ± RECIRCULATION DOOR VACUUM ACTUATOR
3 ± AIR INLET
4 ± BLOWER MOTOR
5 ± EVAPORATOR PROBE CONNECTOR
6 ± CONTROL CABLES
7 ± VACUUM HARNESS
Fig. 53 HVAC Housing Evaporator Connection and
Heater Core Tube Seals
1 ± EVAPORATOR AND CONNECTION
2 ± FOAM SEALS
3 ± HEATER CORE AND TUBES
4 ± HVAC HOUSING LOWER CASE
5 ± HOUSING MOUNTING STUDS
6 ± HOUSING DRAIN
7 ± WIRING
8 ± BLOWER MOTOR AND WHEEL
24 - 34 HEATING AND AIR CONDITIONINGPL
REMOVAL AND INSTALLATION (Continued)