2005 CHRYSLER CARAVAN steering

whenever the ignition switch is in the On position
and the A/C-heater control power is turned on.
The blower motor receives battery current when-
ever the front blower motor relay is energized. The
front blower motor relay output circuit is protected
by a fuse in the Integrated Power Module (IPM)
located in the engine compartment near the battery.
In the manual heater-A/C system, the blower motor
speed is controlled by regulating the path to ground
through the blower control switch and the blower
motor resistor. In the ATC system, the blower motor
speed is controlled by an electronic blower motor
power module, which uses a pulse width modulated
input from the ATC module and feedback from the
blower motor to regulate the blower motor ground
path it provides. The blower motor and wheel are
used to control the velocity of air moving through the
HVAC housing by spinning the blower wheel within
the housing at the selected speed or, in the ATC sys-
tem, at the selected or programmed speed.
DIAGNOSIS AND TESTING
FRONT BLOWER MOTOR
BLOWER MOTOR INOPERATIVE
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.
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring, diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.BLOWER MOTOR ELECTRICAL DIAGNOSIS
(1) Check the fuse (Fuse 10 - 40 ampere) in the
Integrated Power Module (IPM). 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 On position. Be
certain that the A/C-heater control power is turned
on. Check for battery voltage at the fuse (Fuse 10 -
40 ampere) in the IPM. If OK, go to Step 3. If not
OK, check the front blower motor relay.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the front HVAC wire harness connector
for the front blower motor resistor block (Manual
Temperature Control) or the front blower motor
power module (Automatic Temperature Control) from
the resistor or module connector receptacle. Recon-
nect the battery negative cable. Turn the ignition
switch to the On position. Be certain that the A/C-
heater control power is turned on. Check for battery
voltage at the fused front blower motor relay output
circuit cavity of the front HVAC wire harness connec-
tor for the front blower motor resistor block (MTC) or
the front blower motor power module (ATC). If OK,
go to Step 4. If not OK, repair the open fused front
blower motor relay output circuit to the IPM as
required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the front blower motor pigtail wire con-
nector from the connector receptacle of the front
blower motor resistor block (MTC) or the front
blower motor power module (ATC). Use jumper wires
to connect a battery and ground feeds to the blower
motor pigtail wire connector. The blower motor
should operate. If OK with MTC, proceed to diagno-
sis of the front blower motor resistor block (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/BLOWER MOTOR RESISTOR - DIAGNO-
SIS AND TESTING). If OK with ATC, use a DRBIII
scan tool to diagnose the front blower motor power
module. Refer to Body Diagnostic information. If not
OK with MTC or ATC, replace the faulty front blower
motor.
BLOWER MOTOR NOISE OR VIBRATION
Refer to the Blower Motor Noise/Vibration Diagno-
sis chart for basic checks of the blower motor when a
vibration or noise is present (Fig. 7).
24 - 46 DISTRIBUTION - FRONTRS
BLOWER MOTOR (Continued)

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 OR DEATH.
NOTE: The blower motor is located on the passen-
ger side of the vehicle under the instrument panel.
The blower motor can be removed from the vehicle
without having to remove the HVAC housing.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
REMOVAL).
(3) Pull back the carpet to access the front upper
screw that secures the air inlet housing.
(4) Remove the recirculation door actuator (Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS - FRONT/RECIRCULATION DOOR ACTUA-
TOR - REMOVAL).
(5) Remove the recirculation door actuator wire
lead from the routing clip located on the lower air
inlet housing and position the wire lead aside.
(6) Disconnect the blower motor wire lead connec-
tor from the blower motor resistor block or power
module, depending on application.
(7) Remove the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing (Fig. 8).
(8) Remove the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing.
(9) Push the rubber blower motor wire lead grom-
met through the opening in the lower air inlet hous-
ing (Fig. 9).
(10) Feed the blower motor wire lead through the
opening in the lower air inlet housing and remove
the lower air inlet housing from the vehicle.(11) Position the recirculation-air door as neces-
sary to access and remove the three screws that
secure the blower motor to the lower half of the
HVAC housing.
Fig. 8 Lower Air Inlet Housing
1 - BLOWER MOTOR RESISTOR BLOCK/POWER MODULE
2 - BLOWER MOTOR WIRE LEAD
3 - LOWER HVAC HOUSING
4 - UPPER AIR INLET HOUSING
5 - UPPER SCREW (1)
6 - LOWER AIR INLET HOUSING
7 - RECIRCULATION DOOR ACTUATOR
8 - ACTUATOR WIRE LEAD
9 - LOWER SCREW (4)
Fig. 9 Blower Motor Wire Lead Grommet
1 - BLOWER MOTOR WIRE LEAD GROMMET
24 - 48 DISTRIBUTION - FRONTRS
BLOWER MOTOR (Continued)

(12) Gently flex the recirculation air door far down
enough to remove the blower motor and wheel from
the HVAC housing.
(13) Remove the blower motor and wheel from the
HVAC housing. Note the position of the blower motor
mounting tabs (Fig. 10).
INSTALLATION
(1) Position the blower motor and wheel to the
lower half of the HVAC housing. Align the blower
motor mounting tabs to the correct location on the
HVAC housing.
(2) Gently flex the recirculation-air door far down
enough to install the blower motor and wheel into
the HVAC housing.
(3) Position the recirculation-air door as necessary
to install the three screws that secure the blower
motor to the HVAC housing. Tighten the screws to 2
N´m (17 in. lbs.).
(4) Feed the blower motor wire lead through the
opening in the lower air inlet housing and seat the
rubber grommet into the lower air inlet housing.
(5) Position the recirculation-air door pivot into
the lower air inlet housing.
(6) Install the four screws (from the bottom) that
secure the lower air inlet housing to the upper air
inlet housing and the lower HVAC housing. Tighten
the screws to 2 N´m (17 in. lbs.).
(7) Install the one screw (from the top) that
secures the lower air inlet housing to the upper air
inlet housing. Tighten the screws to 2 N´m (17 in.
lbs.).
(8) Connect the blower motor wire lead connector
to the blower motor resistor block or power module,
depending on application.(9) Install the recirculation door actuator (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/RECIRCULATION DOOR ACTUATOR -
INSTALLATION).
(10) Install the recirculation door actuator wire
lead into the routing clip located on the lower air
inlet housing.
(11) Reinstall the carpet.
(12) Install the passenger side cowl trim panel
(Refer to 23 - BODY/INTERIOR/COWL TRIM -
INSTALLATION).
(13) Reconnect the negative battery cable.
(14) Perform the heater-A/C control calibration
procedure (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS - FRONT/A/C-HEATER CON-
TROL - STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION).
DEFROSTER DUCT
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 instrument panel from the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the fasteners that secure the defroster
duct to the instrument panel armature.
(5) Remove the defroster duct from the instrument
panel.Fig. 10 Blower Motor Mounting Tabs
1 - BLOWER MOTOR
2 - RUBBER GROMMET
3 - BLOWER MOTOR CONNECTOR
4 - MOUNTING TABS
RSDISTRIBUTION - FRONT24-49
BLOWER MOTOR (Continued)

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRECAU-
TIONS COULD RESULT IN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Position the defroster duct to the instrument
panel.
(2) Install the fasteners that secure the defroster
duct to the instrument panel armature.
(3) Reinstall the instrument panel in the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRU-
MENT PANEL ASSEMBLY - INSTALLATION).
(4) Reconnect the battery negative cable.
FLOOR DISTRIBUTION DUCTS
REMOVAL
(1) Roll back the carpet on the front floor from
under the instrument panel toward the rear of the
vehicle (Refer to 23 - BODY/INTERIOR/CARPETS
AND FLOOR MATS - REMOVAL).
(2) Lift the center floor distribution duct upward
far enough to disengage its locator hole from the
weld stud on the front floor panel (Fig. 11).
(3) Pull the center floor distribution duct rearward
far enough to disengage it from the floor outlet of the
HVAC housing.
(4) Disassemble the right and/or left floor distribu-
tion ducts from the center floor distribution duct as
required.
INSTALLATION
(1) Assemble the right and/or left floor distribution
ducts onto the center floor distribution duct as
required.
(2) Slide the center floor distribution duct under
the instrument panel center stack far enough to
engage it to the floor outlet of the HVAC housing.
(3) Align the locator hole on the center floor distri-
bution duct with the weld stud on the front floor
panel.
(4) Using hand pressure, push the locator hole of
the center floor distribution duct down over the weld
stud on the front floor panel.(5) Reinstall the carpet onto the front floor panel
and under the instrument panel (Refer to 23 - BODY/
INTERIOR/CARPETS AND FLOOR MATS -
INSTALLATION).
HVAC HOUSING
REMOVAL
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) AND (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
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 PRECAU-
TIONS COULD RESULT IN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Fig. 11 Floor Distribution Ducts - LHD Shown, RHD
Typical
1 - CENTER FLOOR DISTRIBUTION DUCT
2 - RIGHT FLOOR DISTRIBUTION DUCT
3 - LEFT FLOOR DISTRIBUTION DUCT
4 - WELD STUD
24 - 50 DISTRIBUTION - FRONTRS
DEFROSTER DUCT (Continued)

(7) Reconnect the heater hoses to the heater core
tubes (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER HOSE -
INSTALLATION).
(8) Reconnect the suction line and liquid line to
the expansion valve (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - FRONT/SUCTION
LINE - INSTALLATION) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - FRONT/
LIQUID LINE - INSTALLATION).
(9) Install the windshield wiper module (Refer to 8
- ELECTRICAL/WIPERS/WASHERS/WIPER MOD-
ULE - INSTALLATION).
(10) Reconnect the negative battery cable.
(11) Refill the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(12) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(13) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
INSTRUMENT PANEL
DEMISTER DUCTS
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 instrument panel from the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).
(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the fasteners that secure the demister
ducts to the instrument panel armature.
(5) Disengage the demister ducts from the demis-
ter outlets.
(6) Remove the demister ducts 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 demister ducts to the instrument
panel.
(2) Engage the demister ducts to the demister out-
lets.
(3) Install the fasteners that secure the demister
ducts to the instrument panel armature.
(4) Reinstall the instrument panel into the vehicle.
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
24 - 54 DISTRIBUTION - FRONTRS
HVAC HOUSING (Continued)

INSTRUMENT PANEL DUCTS
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 instrument panel from the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - REMOVAL).(3) Place the instrument panel face down on a
suitable work surface. Be certain to take the proper
precautions to protect the face of the instrument
panel from cosmetic damage.
(4) Remove the screws that secure the panel ducts
to the instrument panel armature.
(5) Disengage the panel ducts from the panel out-
lets.
(6) Remove the panel ducts from the instrument
panel.
INSTALLATION
(1) Position the panel ducts to the instrument
panel.
(2) Engage the panel ducts to the panel outlets.
(3) Install the screws that secure the panel ducts
to the instrument panel armature.
(4) Reinstall the instrument panel into the vehicle
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL ASSEMBLY - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
RSDISTRIBUTION - FRONT24-55

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) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
evaporator (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING - DIS-
ASSEMBLY).
(3) Carefully lift the evaporator and its foam wrap
out of the lower half of the HVAC housing as a unit
(Fig. 15). Be certain not to lose the clam shell type
rubber seal that is fitted to the evaporator inlet and
outlet tubes where they exit the HVAC housing.
INSTALLATION
NOTE: If the evaporator is being replaced, add 50
milliliters (1.7 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the A/C compressor in the
vehicle.
(1) Carefully lower the evaporator and its foam
wrap into the lower half of the HVAC housing as a
unit. Be certain that the clam shell type rubber seal
is fitted to the evaporator inlet and outlet tubes
where they exit the HVAC housing.
(2) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
EXPANSION VALVE
DESCRIPTION
The front ªHº valve-type thermal expansion valve
(TXV) is located at the dash panel between the liquid
and suction lines, and the A/C evaporator. The
assembly consists of an aluminum H-valve body and
a thermal sensor. On RG models, the evaporator tem-
perature sensor is installed on the top of the expan-
sion valve.
OPERATION
High-pressure, low temperature liquid refrigerant
from the liquid line passes through the expansion
valve orifice, converting it into a low-pressure, low-
temperature mixture of liquid and gas before it
enters the evaporator coil. A mechanical sensor in the
expansion valve control head monitors the tempera-
ture and pressure of the refrigerant leaving the evap-
orator coil through the suction line, and adjusts the
orifice size at the liquid line to let the proper amount
of refrigerant into the evaporator coil to meet the
vehicle cooling requirements. Controlling the refriger-
ant flow through the A/C evaporator ensures that
none of the refrigerant leaving the evaporator is still
in a liquid state, which could damage the compressor.
The A/C expansion valve is a factory calibrated
unit and cannot be adjusted or repaired and, if faulty
or damaged, it must be replaced.
Fig. 15 HVAC Housing - LHD Shown, RHD Typical
1 - LOWER HVAC HOUSING
2 - UPPER HVAC HOUSING
3 - BLOWER MOTOR AND WHEEL
4 - A/C EVAPORATOR
RSPLUMBING - FRONT24-81
A/C EVAPORATOR (Continued)

heater core inlet and outlet ports. Removable heater
core tubes attach to the ports by use of a sealing
plate secured with a screw to the heater core tank.
This removable heater core tube arrangement allows
the heater core to be serviced without removing the
HVAC housing from the vehicle.
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 door
allows control of the heater output air temperature
by regulating the amount of air that is flowing
through the heater core within the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
FRONT HEATER CORE TUBES
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
core tubes (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/HEATER INLET HOSE -
REMOVAL) and (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/HEATER RETURN
HOSE - REMOVAL).(4) Remove the silencer from beneath the driver
side end of the instrument panel.
NOTE: Take the proper precautions to protect the
carpeting below the heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to clean up any spills.
(5) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 17).
(6) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(7) Install plugs in, or tape over the opened heater
core tube fittings and both heater core ports.
(8) 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.
(9) Remove the heater core tubes and sealing plate
as a unit from beneath the instrument panel.
(10) Use absorbent toweling to clean up any
engine coolant spills from the preceding operation.
Fig. 17 Heater Core Tubes - LHD Shown, RHD
Typical
1 - SEAL
2 - HEATER CORE TUBES
3 - SCREW
4 - HEATER CORE
5 - DISTRIBUTION HOUSING
6 - SEALING PLATE
24 - 84 PLUMBING - FRONTRS
HEATER CORE (Continued)