heater DODGE RAM 2002 Service Repair Manual

AIR CONDITIONING/PLUMBING/REFRIGERANT
OIL - DESCRIPTION)
(2) Install and tighten the high pressure cut-off
switch on the discharge line fitting. The switch
should be hand-tightened onto the discharge line fit-
ting.
(3) Plug the wire harness connector into the high
pressure cut-off switch.
(4) Connect the battery negative cable.
A/C LOW PRESSURE SWITCH
DESCRIPTION
The a/c low pressure switch is located on the top of
the accumulator. The switch is screwed onto an accu-
mulator fitting that contains a Schrader-type valve,
which allows the switch to be serviced without dis-
charging the refrigerant system. The accumulator fit-
ting is equipped with an O-ring to seal the switch
connection.
OPERATION
The a/c low pressure switch is connected in series
electrically with the a/c high pressure switch and the
a/c heater control, between ground and the Power-
train Control Module (PCM). The switch contacts
open and close causing the PCM to turn the compres-
sor clutch on and off. This regulates the refrigerant
system pressure and controls evaporator tempera-
ture. Controlling evaporator temperature prevents
condensate water on the evaporator fins from freez-
ing and obstructing air conditioning system air flow.
The a/c low pressure switch contacts are open
when the suction pressure is about 152-165 kPa
(22-24 psi) or lower. The switch contacts will close
when the suction pressure rises to about 255-296 kPa
(37-43 psi) or above. Lower ambient temperatures,
below about -1É C (30É F), will also cause the switch
contacts to open. This is due to the pressure/temper-
ature relationship of the refrigerant in the system.
The a/c low pressure switch is a factory-calibrated
unit. It cannot be adjusted or repaired and, if faulty
or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C LOW
PRESSURE SWITCH
Before performing diagnosis of the a/c low pressure
switch, be certain that the switch is properly
installed on the accumulator fitting. If the switch is
too loose it may not open the Schrader-type valve in
the accumulator fitting, which will prevent the
switch from correctly monitoring the refrigerant sys-
tem pressure. Also verify that the refrigerant system
has the correct refrigerant charge. (Refer to 24 -HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE)
Remember that lower ambient temperatures, below
about -1É C (30É F), during cold weather will open the
switch contacts and prevent compressor operation
due to the pressure/temperature relationship of the
refrigerant. For circuit descriptions and diagrams,
(Refer to Appropriate Wiring Information).
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the a/c low pressure switch wire har-
ness connector from the switch on the accumulator
fitting.
(3) Install a jumper wire between the two cavities
of the a/c low pressure switch wire harness connector.
(4) Connect a manifold gauge set to the refrigerant
system service ports. (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM SERVICE
EQUIPMENT)
(5) Connect the battery negative cable.
(6) Place the a/c heater mode control switch knob
in any A/C position and start the engine.
(7) Check for continuity between the two terminals
of the low pressure cycling clutch switch. There
should be continuity with a suction pressure reading
of 296 kPa (43 psi) or above, and no continuity with a
suction pressure reading of 172 kPa (25 psi) or below.
If OK, test and repair the A/C switch sense circuit as
required. If not OK, replace the faulty switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the a/c
low pressure switch on the top of the accumulator
(Fig. 20).
(3) Unscrew the a/c low pressure switch from the
fitting on the top of the accumulator.
(4) Remove the O-ring seal from the accumulator
fitting and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the accumulator fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/REFRIGERANT
OIL - DESCRIPTION)
(2) Install and tighten the a/c low pressure switch
on the accumulator fitting. The switch should be
hand-tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the a/c
low pressure switch.
BR/BECONTROLS 24 - 21
A/C HIGH PRESSURE SWITCH (Continued)

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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
blower motor resistor.
(3) Check for continuity between each of the
blower motor switch input terminals of the resistor
and the resistor output terminal. In each case there
should be continuity. If OK, repair the wire harness
circuits between the blower motor switch and the
blower motor resistor or blower motor as required. If
not OK, replace the faulty blower motor resistor.
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Reach under the passenger side end of the
HVAC housing and unplug the wire harness connec-
tor from the blower motor resistor.
(3) Remove the screws that secure the blower
motor resistor to the HVAC housing.
(4) Remove the blower motor resistor from the
HVAC housing (Fig. 23).
INSTALLATION
(1) Install the blower motor resistor into the HVAC
housing and secure it with the mounting screws.
Tighten the mounting screws to 2.2 N´m (20 in. lbs.).
(2) Plug the wire harness connector into the
blower motor resistor.
(3) Connect the battery negative cable.
BLOWER MOTOR SWITCH
DESCRIPTION
The heater-only or a/c heater blower motor is con-
trolled by a four position rotary-type blower motor
switch, mounted in the HVAC control panel. The
switch allows the selection of one of four blower
motor speeds, but can only be turned off by selecting
the Off position with the heater-only or a/c heater
control switch knob.
OPERATION
The blower motor switch directs the blower motor
ground path through the mode control switch to the
blower motor resistor, or directly to ground, as
required to achieve the selected blower motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. The blower
motor switch knob is serviced separately.
Fig. 23 BLOWER MOTOR/RESISTOR
1 - BLOWER MOTOR
2 - BLOWER MOTOR RESISTOR
24 - 24 CONTROLSBR/BE
BLOWER MOTOR RESISTOR BLOCK (Continued)

DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check for battery voltage at the fuse in the
Power Distribution Center (PDC). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the a/c heater control from the instrument
panel. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS/A/C HEATER CONTROL -
REMOVAL) Check for continuity between the ground
circuit cavity of the a/c heater control wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 3. If not OK, repair the open
circuit to ground as required.
(3) With the a/c heater control wire harness con-
nector unplugged, place the a/c heater mode control
switch knob in any position except the Off position.
Check for continuity between the ground circuit ter-
minal and each of the blower motor driver circuit ter-
minals of the a/c heater control as you move the
blower motor switch knob to each of the four speed
positions. There should be continuity at each driver
circuit terminal in only one blower motor switch
speed position. If OK, test and repair the blower
driver circuits between the a/c heater control connec-
tor and the blower motor resistor as required. If not
OK, replace the faulty a/c heater control unit.
REMOVAL
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or a/c
heater control unit must be replaced. (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL) The blower motor
switch knob is serviced separately.
BLEND DOOR ACTUATOR
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Turn the ignition switch to the run position.
(2) Locate the temperature control knob in the mid
(12 o'clock) position.
(3) Turn the ignition switch to the off position.
(4) Disconnect and isolate the battery negative
cable.
(5) Remove the instrument panel from the vehi-
cle(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(6) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(7) Unplug the wire harness connector from the
blend door actuator (Fig. 24).
(8) Remove the two mounting screws which secure
the actuator to the housing.
(9) Slide the blend door actuator off the blend door
shaft.
NOTE: A black plastic coupler may be attached to
the blend door shaft. Remove the coupler and
inspect for damage. Reinstall if there is no damage
found.
INSTALLATION
NOTE: Before installing the blend door actuator, be
certain that the blend door is not binding and is
capable of full travel in both directions.
(1) Align the actuator with the blend door shaft
and rotate the actuator to align it to the mounting
bosses on the HVAC housing.
(2) Align and install the actuator screws. Tighten
the mounting screws to 2.2 N´m (20 in. lbs.).
(3) Plug in the wire harness connector to the blend
door actuator.
BR/BECONTROLS 24 - 25
BLOWER MOTOR SWITCH (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
DISTRIBUTION
DESCRIPTION..........................30
AIR OUTLETS
REMOVAL..............................31
INSTALLATION..........................31
BLOWER MOTOR
DESCRIPTION..........................31
OPERATION............................31
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - BLOWER
MOTOR ..............................32
REMOVAL..............................32
INSTALLATION..........................32
DEFROSTER DUCTS
REMOVAL..............................33
INSTALLATION..........................33
HVAC HOUSING
REMOVAL..............................34DISASSEMBLY..........................35
ASSEMBLY.............................36
INSTALLATION..........................36
INSTRUMENT PANEL DEMISTER DUCTS
REMOVAL..............................36
INSTALLATION..........................36
INSTRUMENT PANEL DUCTS
REMOVAL..............................37
INSTALLATION..........................37
BLEND DOOR
REMOVAL..............................37
INSTALLATION..........................37
MODE DOOR
REMOVAL..............................37
INSTALLATION..........................38
RECIRCULATION DOOR
REMOVAL..............................38
INSTALLATION..........................39
DISTRIBUTION
DESCRIPTION - HVAC SYSTEM AIRFLOW
Outside air enters the vehicle through the cowl top
opening at the base of the windshield, and passes
through a plenum chamber to the HVAC system
blower housing (Fig. 1). Air flow velocity can then be
adjusted with the blower motor switch on the a/c
heater control panel. The air intake openings must
be kept free of snow, ice, leaves, and other obstruc-
tions for the HVAC system to receive a sufficient vol-
ume 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.
Fig. 1 HVAC SYSTEM AIRFLOW
1 - DEFROST OUTLET
2 - OUTSIDE AIR INLET
3 - RECIRCULATION INLET
4 - FLOOR OUTLET
5 - PANEL OUTLET
24 - 30 DISTRIBUTIONBR/BE

AIR OUTLETS
REMOVAL - DEMISTER GRILLES
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry at the perimeter edges of
the demister grille to release the snap features from
the instrument panel top cover.
(2) Remove the demister grille from the instru-
ment panel.
REMOVAL - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS
INSTALLED IN THE PASSENGER SIDE AIRBAG
DOOR PANEL OUTLET HOUSINGS MUST NEVER
BE REINSTALLED FOLLOWING REMOVAL FOR ANY
REASON. THEY MUST BE REPLACED WITH NEW
BARRELS. FAILURE TO OBSERVE THIS WARNING
COULD RESULT IN OCCUPANT INJURIES UPON
AIRBAG DEPLOYMENT.
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry near the center of either
side of the panel outlet barrel to release the snap-fit
pivots on the barrel from the pivot pins in the outlet
housing of the passenger side airbag module or the
instrument cluster bezel (Fig. 2).
(2) Remove the barrel from the panel outlet hous-
ing.
INSTALLATION - DEMISTER GRILLES
(1) To install the demister grille, position the grille
in the opening of the instrument panel top cover and
press inwards firmly and evenly near the center of
both sides of the grille until it snaps into place.
INSTALLATION - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS
INSTALLED IN THE PASSENGER SIDE AIRBAG
DOOR PANEL OUTLET HOUSINGS MUST NEVER
BE REINSTALLED FOLLOWING REMOVAL FOR ANY
REASON. THEY MUST BE REPLACED WITH NEW
BARRELS. FAILURE TO OBSERVE THIS WARNING
COULD RESULT IN OCCUPANT INJURIES UPON
AIRBAG DEPLOYMENT.
(1) To install a new panel outlet barrel, position
the barrel in the outlet housing and press inwards
firmly and evenly near the center of both sides of the
panel outlet barrel until the pivots snap into place.
BLOWER MOTOR
DESCRIPTION
The blower motor and blower wheel are located in
the passenger side end of the HVAC housing, below
the glove box. The blower motor controls the velocity
of the air flowing through the HVAC housing by spin-
ning a squirrel cage-type blower wheel within the
housing at the selected speed. The blower motor and
blower wheel can be serviced from the passenger
compartment side of the housing.
OPERATION
The blower motor will only operate when the igni-
tion switch is in the On position, and the a/c heater
mode control switch knob is in any position, except
Off. The blower motor receives a fused battery feed
through the blower motor relay whenever the igni-
tion switch is in the On position.
The blower motor battery feed circuit is protected
by a fuse in the Power Distribution Center (PDC).
The blower motor relay control circuit is protected by
a fuse in the junction block. Blower motor speed is
controlled by regulating the ground path through the
a/c heater mode control switch, the blower motor
switch, and the blower motor resistor.
The blower motor and blower wheel cannot be
repaired and, if faulty or damaged, they must be
replaced. The blower motor and blower wheel may be
serviced separately, although if the motor is to be
replaced, a blower wheel will come as part of a pre-
balanced assembly.
Fig. 2 PANEL OUTLET BARRELS
1 - DEFROSTER OUTLETS
2 - DEMISTER OUTLET GRILLE
3 - PANEL OUTLET BARRELS
4 - DEMISTER OUTLET GRILLE
BR/BEDISTRIBUTION 24 - 31

DIAGNOSIS AND TESTING - BLOWER MOTOR
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). Possible causes of
an inoperative blower motor include:
²Faulty fuse
²Faulty blower motor circuit wiring or wire har-
ness connectors
²Faulty blower motor resistor
²Faulty blower motor relay
²Faulty blower motor switch
²Faulty a/c heater mode control switch
²Faulty blower motor.
Possible causes of the blower motor not operating
in all speeds include:
²Faulty fuse
²Faulty blower motor switch
²Faulty blower motor resistor
²Faulty blower motor relay
²Faulty blower motor circuit wiring or wire har-
ness connectors.
VIBRATION
Possible causes of blower motor vibration include:
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower wheel out of balance or deformed
²Blower motor faulty.
NOISE
To verify that the blower is the source of the noise,
unplug the blower motor wire harness connector and
operate the HVAC system. If the noise goes away,
possible causes include:
²Foreign material in the HVAC housing
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower motor faulty.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the blower motor cooling tube from
the nipple on the blower motor housing (Fig. 3).
(3) Disengage the blower motor wire harness from
the wire harness retainer.
(4) Unplug the blower motor wire harness connec-
tor from the HVAC housing wire harness.
(5) Remove the three screws that secure the
blower motor and blower wheel assembly to the
HVAC housing.
(6) Lower the blower motor and wheel assembly,
and cover, from the HVAC housing.
(7) Remove the blower wheel retainer clip and
remove the wheel from the blower motor shaft (Fig.
4).
INSTALLATION
(1) If installing the blower motor wheel only, press
the blower wheel hub onto the blower motor shaft.
Be sure the flat on the blower motor shaft is indexed
to the flat on the inside of the blower wheel hub.
(2) Install the retainer clip over the blower wheel
hub. The ears of the retainer clip must be indexed
over the flats on the blower motor shaft and blower
wheel hub.
Fig. 3 BLOWER MOTOR REMOVE/INSTALL
1 - BLOWER MOTOR HOUSING
2 - COOLING TUBE
3 - ELECTRICAL CONNECTOR
24 - 32 DISTRIBUTIONBR/BE
BLOWER MOTOR (Continued)

(2) Roll the instrument panel assembly up, and
fasten it properly to the vehicle(Refer to 23 - BODY/
INSTRUMENT PANEL/INSTRUMENT PANEL
ASSEMBLY - INSTALLATION).
HVAC HOUSING
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
WARNING: IF THE VEHICLE IS EQUIPPED WITH AIR
CONDITIONING, REVIEW THE WARNINGS AND
CAUTIONS IN PLUMBING BEFORE PERFORMING
THE FOLLOWING OPERATION. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - WARNING)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION)
The HVAC housing assembly must be removed
from the vehicle and disassembled for service access
of the heater core, a/c evaporator, and each of the
various mode control doors.
Fig. 6 DEFROSTER AND DEMISTER DUCT
1 - DEMISTER TUBE
2 - INSTRUMENT PANEL TOP COVER3 - BRACKETS
4 - DEFROSTER AND DEMISTER DUCT
Fig. 7 DEFROSTER AND DEMISTER DUCT
ADAPTER REMOVE/INSTALL
1 - DEFROSTER AND DEMISTER DUCT ADAPTER
2 - HEATER-A/C HOUSING
24 - 34 DISTRIBUTIONBR/BE
DEFROSTER DUCTS (Continued)

(1) Disconnect and isolate the battery negative
cable.
(2) If the vehicle is not equipped with air condi-
tioning, go to Step 6. If the vehicle is equipped with
air conditioning, recover the refrigerant from the sys-
tem. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Remove the instrument panel from the vehicle.
Refer to Instrument Panel System for the procedures.
(4) Disconnect the liquid line refrigerant line fit-
ting from the evaporator inlet tube. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(5) Remove the accumulator. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/ACCU-
MULATOR - REMOVAL) Install plugs in, or tape
over all of the opened refrigerant line fittings.
(6) Drain the engine cooling system(Refer to 7 -
COOLING - STANDARD PROCEDURE) and (Refer
to 7 - COOLING - STANDARD PROCEDURE).
(7) Disconnect the heater hoses from the heater
core tubes. Refer to Cooling for the procedures.
Install plugs in, or tape over the opened heater core
tubes.
(8) Remove the Powertrain Control Module (PCM)
from the dash panel and set it aside, but do not
unplug the PCM wire harness connectors. Refer to
Electronic Control Modules for the procedures.
(9) Remove the nuts from the HVAC housing
mounting studs on the engine compartment side of
the dash panel.
(10) Remove the nuts that secure the HVAC hous-
ing to the mounting studs on the passenger compart-
ment side of the dash panel (Fig. 8).
(11) Pull the HVAC housing rearward far enough
for the mounting studs and the evaporator conden-
sate drain tube to clear the dash panel holes.
(12) Remove the HVAC housing from the vehicle.
REMOVAL - HVAC HOUSING INLET BAFFLE
(1) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(2) Slide the HVAC housing inlet baffle (Fig. 9) all
the way to one side of the cowl plenum opening.
(3) Pull downwards sharply and firmly on the
opposite side of the HVAC housing inlet baffle to dis-
engage the snap features from the cowl plenum open-
ing.
(4) Remove the HVAC housing inlet baffle from the
cowl plenum panel.DISASSEMBLY
(1) Place the HVAC housing upside down on a
work bench.
(2) Remove the screw that secures the floor duct to
the bottom of the HVAC housing and slide the floor
duct off of the center heat duct adaptor.
(3) Unsnap the center heat duct adaptor from the
bottom of the HVAC housing and remove the screw
that was hidden by the adaptor.
(4) Remove the remaining screws on the bottom of
the HVAC housing that secure the two housing
halves together.
Fig. 8 HVAC HOUSING REMOVE/INSTALL
1 - BODY ASSEMBLY
2 - HVAC HOUSING
Fig. 9 HVAC HOUSING INLET BAFFLE REMOVE/
INSTALL
1 - RIGHT A-PILLAR
2 - INLET BAFFLE
3 - COWL PLENUM OPENING
BR/BEDISTRIBUTION 24 - 35
HVAC HOUSING (Continued)

(5) Place the HVAC housing right side up on the
work bench.
(6) Separate the top half of the HVAC housing
from the bottom half and set it aside.
ASSEMBLY
(1) Position the top half of the HVAC housing over
the bottom half. Be certain that the mode door pivot
pins are properly inserted in their pivot holes.
(2) Place the HVAC housing upside down on the
work bench.
(3) Install and tighten the screws on the bottom of
the HVAC housing that secure the two housing
halves together. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(4) Snap the center heat duct adaptor onto the bot-
tom of the HVAC housing.
(5) Slide the floor duct onto the center heat duct
adaptor and secure it with a screw to the bottom of
the HVAC housing. Tighten the mounting screw to
2.2 N´m (20 in. lbs.).
INSTALLATION
(1) Position the HVAC housing to the dash panel.
Be certain that the evaporator condensate drain tube
and the housing mounting studs are inserted into
their correct mounting holes.
(2) Install the nuts that secure the HVAC housing
to the mounting studs on the passenger compartment
side of the dash panel. Tighten the nuts to 4.5 N´m
(40 in. lbs.).
(3) Install and tighten the nuts onto the HVAC
housing mounting studs on the engine compartment
side of the dash panel. Tighten the nuts to 7 N´m (60
in. lbs.).
(4) Unplug or remove the tape from the heater
core tubes. Connect the heater hoses to the heater
core tubes and fill the engine cooling system(Refer to
7 - COOLING - STANDARD PROCEDURE) and
(Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(5) If the vehicle is not equipped with air condi-
tioning, go to Step 10. If the vehicle is equipped with
air conditioning, install the accumulator. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
ACCUMULATOR - INSTALLATION) Connect the
accumulator inlet tube coupler to the evaporator out-
let tube. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
A/C LINE COUPLERS)
(6) Unplug or remove the tape from the liquid line
and the evaporator inlet tube fittings. Connect the
liquid line coupler to the evaporator inlet tube. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - A/C LINE COU-
PLERS)(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(8) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(9) Reinstall the PCM to the dash panel. Refer to
Electronic Control Modules for the procedures.
(10) Reinstall the instrument panel in the vehi-
cle(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY -
INSTALLATION).
(11) Connect the battery negative cable.
(12) Start the engine and check for proper opera-
tion of the heating and air conditioning systems.
INSTALLATION - HVAC HOUSING INLET
BAFFLE
(1) Install the HVAC housing inlet baffle in the
cowl plenum panel.
(2) Slide the HVAC housing inlet baffle to engage
the snap features.
(3) Make certain that the snap features on each
side of the adapter are fully engaged with the sides
of the plenum panel opening. This must be a water
tight connection to prevent leaks.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
INSTRUMENT PANEL
DEMISTER DUCTS
REMOVAL
The defroster duct and the main demister duct are
a single molded plastic unit. The defroster outlet
grilles are heat-staked to the defroster outlets and
cannot be serviced separately. The demister tubes on
each end of the main demister duct are only serviced
in the instrument panel assembly. (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL)
INSTALLATION
The defroster duct and the main demister duct are
a single molded plastic unit. The defroster outlet
grilles are heat-staked to the defroster outlets and
cannot be serviced separately. The demister tubes on
each end of the mail demister duct are only serviced
in the instrument panel assembly(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - INSTALLATION).
24 - 36 DISTRIBUTIONBR/BE
HVAC HOUSING (Continued)

PLUMBING
TABLE OF CONTENTS
page page
PLUMBING
DESCRIPTION..........................40
OPERATION............................41
WARNING..............................42
CAUTION..............................42
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS.......................43
STANDARD PROCEDURE
STANDARD PROCEDURE - A/C LINE
COUPLERS...........................44
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT...........45
STANDARD PROCEDURE - REFRIGERANT
RECOVERY...........................45
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE....................46
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE......................46
SPECIFICATIONS........................46
A/C COMPRESSOR
DESCRIPTION..........................46
OPERATION............................46
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
COMPRESSOR........................47
REMOVAL..............................47
INSTALLATION..........................48
A/C CONDENSER
DESCRIPTION..........................49
OPERATION............................49
REMOVAL..............................49
INSTALLATION..........................50
SUCTION AND DISCHARGE LINE
REMOVAL..............................51
INSTALLATION..........................52LIQUID LINE
REMOVAL..............................52
INSTALLATION..........................52
A/C EVAPORATOR
DESCRIPTION..........................53
OPERATION............................53
REMOVAL..............................53
INSTALLATION..........................53
A/C ORIFICE TUBE
DESCRIPTION..........................54
OPERATION............................54
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - FIXED
ORIFICE TUBE.........................54
REMOVAL..............................54
INSTALLATION..........................54
ACCUMULATOR
DESCRIPTION..........................55
OPERATION............................55
REMOVAL..............................55
INSTALLATION..........................55
HEATER CORE
DESCRIPTION..........................56
OPERATION............................56
REMOVAL..............................56
INSTALLATION..........................56
REFRIGERANT
DESCRIPTION..........................56
OPERATION............................57
REFRIGERANT OIL
DESCRIPTION..........................57
OPERATION............................57
STANDARD PROCEDURE
STANDARD PROCEDURE - REFRIGERANT
OIL LEVEL............................57
PLUMBING
DESCRIPTION - A/C LINE COUPLERS
Spring-lock type refrigerant line couplers are used
to connect many of the refrigerant lines and other
components to the refrigerant system. These couplers
require a special tool for disengaging the two coupler
halves.
DESCRIPTION- REFRIGERANT LINES
The refrigerant lines and hoses are used to carry
the refrigerant between the various air conditioning
system components. A barrier hose design with a
nylon tube, which is sandwiched between rubber lay-
ers, is used for the R-134a air conditioning system on
this vehicle. This nylon tube helps to further contain
the R-134a refrigerant, which has a smaller molecu-
lar structure than R-12 refrigerant. The ends of the
refrigerant hoses are made from lightweight alumi-
num or steel, and commonly use braze-less fittings.
24 - 40 PLUMBINGBR/BE