heater CHRYSLER CARAVAN 2003 Service Manual

(10) Reconnect the body wire harness connector for
the rear heater-A/C unit housing to the rear HVAC
wire harness connector located near the expansion
valve at the back of the unit.
(11) Reinstall the auxiliary A/C distribution duct
onto 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 - INSTALLATION).
(12) Reinstall the right quarter trim panel and
right D-pillar trim panel onto the quarter inner
panel. (Refer to 23 - BODY/INTERIOR/QUARTER
TRIM PANEL - INSTALLATION).
(13) Raise and support the vehicle.
(14) Install and tighten the three nuts that secure
the rear heater-A/C unit mounting studs to the rear
floor panel behind the right rear wheel housing.
Tighten the nuts to 9 N´m (80 in. lbs.).
(15) Remove the tape or plugs from the underbody
liquid line and suction line fittings and both ports in
the rear heater-A/C unit evaporator extension line
sealing plate that extends through the rear floor
panel behind the right rear wheel housing.
(16) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the liquid line and
suction line fittings.
(17) Reconnect the underbody refrigerant line seal-
ing plate to the evaporator extension line sealing
plate.
(18) Install and tighten the screw that secures the
underbody refrigerant line sealing plate to the evap-
orator extension line sealing plate. Tighten the screw
to 23 N´m (17 ft. lbs.).
(19) Lower the vehicle.
(20) Reconnect the battery negative cable.
(21) Refill the engine cooling system. (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOLING
SYSTEM REFILL).
(22) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(23) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
(24) Run the HVAC Cooldown test to verify proper
operation(Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING).REAR HEATER DISTRIBUTION
DUCT
REMOVAL
(1) Remove the trim from the right quarter inner
panel. (Refer to 23 - BODY/INTERIOR/RIGHT
QUARTER TRIM PANEL - REMOVAL).
(2) Remove the two screws that secure the rear
heater distribution duct to the right quarter inner
panel (Fig. 9).
(3) Slide the rear heater distribution duct forward
far enough to disengage it from the outlet on the
front of the rear heater-air conditioner unit housing.
(4) Remove the rear heater distribution duct from
the vehicle.
INSTALLATION
(1) Align the inlet end of rear heater distribution
duct with the outlet on the front of the rear heater-
air conditioner unit housing.
(2) Slide the rear heater distribution duct rear-
ward far enough to fully engage the inlet end of the
duct with the outlet on the front of the rear heater-
air conditioner unit housing.
(3) Install and tighten the two screws that secure
the rear heater distribution duct to the right quarter
inner panel. Tighten the screws to 1.6 N´m (14 in.
lbs.).
(4) Reinstall the trim onto the right quarter inner
panel. (Refer to 23 - BODY/INTERIOR/RIGHT
QUARTER TRIM PANEL - INSTALLATION).
Fig. 9 Rear Heater Distribution Duct
1 - REAR HEATER DISTRIBUTION DUCT
2 - REAR HEATER-A/C UNIT OUTLET
3 - SCREW (2)
RSDISTRIBUTION - REAR24-59
REAR HEATER-A/C HOUSING (Continued)
ProCarManuals.com

PLUMBING - FRONT
TABLE OF CONTENTS
page page
PLUMBING - FRONT
WARNING
WARNING...........................61
WARNING - A/C PLUMBING.............61
CAUTION - A/C PLUMBING...............61
A/C COMPRESSOR
DESCRIPTION.........................63
OPERATION...........................63
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE DIAGNOSIS....................63
REMOVAL
REMOVAL - COMPRESSOR - 2.4/3.3/3.8L
ENGINES............................64
REMOVAL - COMPRESSOR MOUNTING
BRACKET - 2.4L ENGINE...............65
INSTALLATION
INSTALLATION - COMPRESSOR..........65
INSTALLATION - COMPRESSOR
MOUNTING BRACKET - 2.4L ENGINE......66
CONDENSER
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL.............................66
INSTALLATION.........................67
DISCHARGE LINE
REMOVAL.............................68
INSTALLATION.........................69
EVAPORATOR
DESCRIPTION.........................69
OPERATION...........................70
REMOVAL.............................70
INSTALLATION.........................71
EXPANSION VALVE
DESCRIPTION.........................72
OPERATION...........................72
DIAGNOSIS AND TESTING - EXPANSION
VALVE ..............................72
REMOVAL.............................73
INSTALLATION.........................74
HEATER CORE
DESCRIPTION.........................74
OPERATION...........................74
REMOVAL
REMOVAL- HEATER CORE EXTENSION
TUBES.............................75REMOVAL - HEATER CORE.............76
INSTALLATION
INSTALLATION- HEATER CORE
EXTENSION TUBES...................77
INSTALLATION - HEATER CORE..........78
HEATER HOSE
REMOVAL.............................78
INSTALLATION.........................80
LIQUID LINE
REMOVAL.............................80
INSTALLATION.........................82
RECEIVER/DRIER
DESCRIPTION.........................83
OPERATION...........................84
REMOVAL.............................84
INSTALLATION.........................84
REFRIGERANT
DESCRIPTION.........................85
OPERATION...........................85
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM CHARGE LEVEL...............85
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS......................86
STANDARD PROCEDURE
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT..........87
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE.....................88
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE...................89
STANDARD PROCEDURE - REFRIGERANT
RECOVERY..........................89
REFRIGERANT OIL
DESCRIPTION.........................90
OPERATION...........................90
STANDARD PROCEDURE - REFRIGERANT
OIL LEVEL...........................90
SUCTION LINE
REMOVAL.............................90
INSTALLATION.........................91
SERVICE PORTS
REMOVAL.............................92
INSTALLATION.........................93
24 - 60 PLUMBING - FRONTRS
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PLUMBING - FRONT
WARNING
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.
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/ORTHROAT. 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 AND
ALTITUDE 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.
RSPLUMBING - FRONT24-61
ProCarManuals.com

(9) Remove the nut that secures the discharge line
fitting to the top of the compressor (Fig. 8).
(10) Disconnect the discharge line fitting from the
compressor discharge port.
(11) Remove the seals from the discharge line fit-
ting and discard.
(12) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(13) Remove the discharge line from the engine
compartment.
INSTALLATION
(1) Position the discharge line into the engine com-
partment.
(2) Remove the tape or plugs from the compressor
discharge port and the discharge line fitting.
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(4) Install a new dual plane seal and reconnect the
discharge line fitting to the compressor discharge
port on the top of the compressor.
(5) Install and tighten the nut that secures the
discharge line fitting to the compressor. Tighten the
nut to 23 N´m (17 ft. lbs.).
(6) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(8) Install a new dual plane seal and reconnect the
discharge line fitting to the condenser inlet port on
the right side of the cooling module.
(9) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 23 N´m (17 ft. lbs.).
(10) Position the radiator sight shield onto the
radiator closure panel crossmember.
(11) Install and tighten the five small screws that
secure the front fascia grille inserts to the radiator
sight shield. Tighten the screws to 2 N´m (18 in. lbs.).
(12) Install and tighten the two large screws that
secure the front fascia and the outboard ends of the
radiator sight shield to the radiator closure panel
crossmember. Tighten the screws to 6 N´m (53 in.
lbs.).
(13) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(14) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM CHARGE).
EVAPORATOR
DESCRIPTION
The evaporator is located in the heater-A/C unit
housing, behind the instrument panel. The evapora-
tor is positioned in the heater-A/C housing so that all
air that enters the housing must pass over the fins of
the evaporator before it is distributed through the
system ducts and outlets. However, air passing over
the evaporator fins will only be conditioned when the
compressor is engaged and circulating refrigerant
Fig. 7 Condenser Connections
1 - CONDENSER
2 - DISCHARGE LINE FITTING
3 - LIQUID LINE FITTING
4 - NUT
Fig. 8 Discharge Line
1 - DISCHARGE LINE
2 - NUT
3 - DISCHARGE LINE FITTING
4 - STUD
5 - DISCHARGE PORT
RSPLUMBING - FRONT24-69
DISCHARGE LINE (Continued)
ProCarManuals.com

through the evaporator tubes. The heater-A/C unit
housing must be removed from the vehicle to access
the evaporator for service. The evaporator cannot be
adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
Refrigerant enters the evaporator from the expan-
sion valve as a low-temperature, low-pressure liquid/
vapor mixture. As air flows over the fins of the evap-
orator, the humidity in the air condenses on the fins,
and the heat from the air is absorbed by the refrig-
erant. Heat absorption causes the refrigerant to boil
and vaporize. The refrigerant becomes a low-pressure
gas when it leaves the evaporator.
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 - FRONT - WARNING - A/C PLUMBING),
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING),
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - HEATER PLUMB-
ING).
(1) Remove the HVAC unit housing from the vehi-
cle. (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION - FRONT/HVAC HOUSING -
REMOVAL).
(2) Remove the heater core tubes from the heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
REMOVAL - HEATER CORE TUBES).
(3) Remove and discard the foam seal from the
HVAC housing seal flange around the fresh air inlet
opening and the expansion valve/evaporator tube
opening on the dash panel side of the unit.
(4) Remove the expansion valve from the evapora-
tor inlet and outlet tube fittings. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/EXPANSION VALVE - REMOVAL).
(5) Disconnect the HVAC wire harness connector
for the blower motor from the motor connector recep-
tacle on the bottom of the outboard end of the evap-
orator housing.
(6) Disengage the HVAC wire harness from the
routing clips molded into the outside of the HVAC
housing components.
(7) Remove the four screws from the dash panel
side of the unit that secure the top of the distribution
housing to the inboard end of the evaporator housing
(Fig. 9).(8) Pull the top of the distribution housing away
from the evaporator housing far enough to disengage
the two hook formations on the bottom of the distri-
bution housing from the two receptacles on the evap-
orator housing (Fig. 10).
(9) Remove the two screws that secure the upper
intake air housing to the lower intake air housing.
(10) Remove the three screws that secure the
upper intake air housing to the top of the outboard
end of the evaporator housing. Be certain not to miss
the screw located just inside the inboard side of the
fresh air intake opening.
(11) Remove the upper intake air housing from the
top of the evaporator housing to expose the recircu-
Fig. 9 HVAC Housing
1 - DISTRIBUTION HOUSING
2 - SCREWS (3)
3 - HVAC WIRING HARNESS
4 - ROUTING CLIP
5 - EVAPORATOR HOUSING
Fig. 10 Distribution Housing Hooks
1 - RECEPTACLES ON EVAPORATOR HOUSING
2 - HOOKS ON DISTRIBUTION HOUSING
24 - 70 PLUMBING - FRONTRS
EVAPORATOR (Continued)
ProCarManuals.com

the notched area between the upper and lower hous-
ing halves.
(3) Install and tighten the twelve screws around
the perimeter of the evaporator housing that secure
the upper housing half to the lower half. Tighten the
screws to 2 N´m (18 in. lbs.).
(4) Position the upper half of the recirculation air
door onto the lower half of the door.
(5) Install and tighten the two screws that secure
the upper half of the recirculation air door to the
lower half of the door. Tighten the screws to 2 N´m
(18 in. lbs.).
(6) Position the upper intake air housing onto the
top of the evaporator housing over the recirculation
air door and the blower wheel housing. Be certain
that the upper pivot of the recirculation air door is
captured in the pivot receptacle of the upper intake
air housing.
(7) Install and tighten the three screws that secure
the upper intake air housing to the top of the out-
board end of the evaporator housing. Be certain not
to miss the screw located just inside the inboard side
of the fresh air intake opening. Tighten the screws to
2 N´m (18 in. lbs.).
(8) Install and tighten the two screws that secure
the upper intake air housing to the lower intake air
housing. Tighten the screws to 2 N´m (18 in. lbs.).
(9) Engage the two hook formations on the bottom
of the distribution housing in the two receptacles on
the evaporator housing.
(10) Roll the top of the distribution housing up
into position against the evaporator housing.
(11) Install and tighten the three screws from the
dash panel side of the unit that secure the top of the
distribution housing to the inboard end of the evapo-
rator housing. Tighten the screws to 2 N´m (18 in.
lbs.).
(12) Engage the HVAC wire harness in the routing
clips molded into the outside of the HVAC housing
components.
(13) Reconnect the HVAC wire harness connector
for the blower motor with the motor connector recep-
tacle on the bottom of the outboard end of the evap-
orator housing.
(14) Reinstall the expansion valve onto the evapo-
rator inlet and outlet tube fittings. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
FRONT/EXPANSION VALVE - INSTALLATION).
(15) Install a new foam seal onto the HVAC hous-
ing seal flange around the fresh air inlet opening and
the expansion valve/evaporator tube opening on the
dash panel side of the unit.
(16) Reinstall the heater core tubes into the heater
core. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - FRONT/HEATER CORE -
INSTALLATION - HEATER CORE TUBES).(17) Reinstall the HVAC unit housing into the
vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - FRONT/HVAC HOUS-
ING - INSTALLATION).
(18) Run the HVAC Control Actuator Calibration
procedure(Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING)(Refer to 24
- HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING).
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 evaporator coil. The
assembly consists of an H-valve body and a thermal
sensor. High-pressure, low temperature liquid refrig-
erant from the liquid line passes through the expan-
sion valve orifice, converting it into a low-pressure,
low-temperature mixture of liquid and gas before it
enters the evaporator coil. The expansion valve is a
factory calibrated unit and cannot be adjusted or
repaired. If faulty or damaged, the expansion valve
must be replaced.
OPERATION
A mechanical sensor in the expansion valve control
head monitors the temperature and pressure of the
refrigerant leaving the evaporator 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 require-
ments. Controlling the refrigerant flow through the
evaporator ensures that none of the refrigerant leav-
ing the evaporator is still in a liquid state, which
could damage the compressor. The thermo sensor
measures refrigerant suction gas temperature which
is monitored by the a/c control assembly.
DIAGNOSIS AND TESTING - EXPANSION VALVE
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 - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
NOTE: The expansion valve should only be tested
following testing of the compressor.
24 - 72 PLUMBING - FRONTRS
EVAPORATOR (Continued)
ProCarManuals.com

NOTE: Liquid CO2is required to test the expansion
valve. This material is available from most welding
supply facilities. Liquid CO
2is also available from
companies which service and sell fire extinguish-
ers.
When testing the expansion valve, the work area
and the vehicle temperature must be 21É to 27É C
(70É to 85É F). To test the expansion valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set the heater-air conditioner controls so that
the compressor is operating, the temperature control
is in the highest temperature position, the mode door
is directing the output to the floor outlets, and the
blower is operating at the highest speed setting.
(4) Start the engine and allow it to idle at 1000
rpm. After the engine has reached normal operating
temperature, allow the passenger compartment to
heat up. This will create the need for maximum
refrigerant flow into the evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 to 1655
kPa (140 to 240 psi). The suction (low pressure)
gauge should read 140 kPa to 207 kPa (20 psi to 30
psi). If OK, go to Step 6. If not OK, replace the faulty
expansion valve.
WARNING:
PROTECT THE SKIN AND EYES FROM EXPOSURE
TO LIQUID CO
2. PERSONAL INJURY CAN RESULT.
(6) If the suction (low pressure) gauge reads
within the specified range, freeze the expansion valve
control head for 30 seconds using liquid CO
2or
another suitable super-cold material.Do not spray
R-134a or R-12 refrigerant on the expansion
valve control head for this test.The suction (low
pressure) gauge reading should drop by 10 psi. If OK,
go to Step 7 If not OK, replace the faulty expansion
valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 140 kPa to 240 kPa (20 psi to 30 psi). If not
OK, replace the faulty expansion valve.
(8) When expansion valve testing is complete, test
the overall air conditioner performance. (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
Remove all test equipment before returning the vehi-
cle to service.
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 - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
(5) Disconnect the headlamp and dash wire har-
ness connector for the A/C pressure transducer from
the transducer on the front liquid line rear section
(Fig. 14).
(6) Remove the screw that secures the front liquid
line rear section fitting to the top of the filter-drier.
(7) Disconnect the liquid line fitting from the fil-
ter-drier outlet port.
(8) Remove the seal from the liquid line fitting and
discard.
Fig. 14 Expansion Valve
1 - A/C PRESSURE TRANSDUCER
2 - EVAPORATOR TEMPERATURE SENSOR
3 - EXPANSION VALVE
4 - SUCTION LINE
5 - HIGH SIDE SERVICE PORT
6 - FRONT LIQUID LINE REAR SECTION
RSPLUMBING - FRONT24-73
EXPANSION VALVE (Continued)
ProCarManuals.com

(9) Install plugs in, or tape over the opened liquid
line fitting and the filter-drier outlet port.
(10) Remove the nut that secures the suction line
and liquid line fittings to the stud on the expansion
valve.
(11) Disconnect the suction line and liquid line fit-
tings from the expansion valve and move the lines
out of the way.
(12) Remove the seals from the suction line and
liquid line fittings and discard.
(13) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(14) Remove the two screws that secure the expan-
sion valve to the evaporator tube tapping plate.
(15) Disconnect the HVAC wire harness connector
for the evaporator temperature sensor from the sen-
sor on the top of the expansion valve.
(16) Remove the expansion valve from the evapo-
rator inlet and outlet tube fittings.
(17) Remove the seals from the evaporator inlet
and outlet tube fittings and discard.
(18) Install plugs in, or tape over the opened evap-
orator inlet and outlet tube fittings and both expan-
sion valve ports.
INSTALLATION
(1) Remove the tape or plugs from the evaporator
inlet and outlet tube fittings and both ports on the
back of the expansion valve.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
inlet and outlet tube fittings.
(3) Position the expansion valve onto the evapora-
tor inlet and outlet tube fittings.
(4) Install and tighten the two screws that secure
the expansion valve to the evaporator tube tapping
plate plate. Tighten the screws to 11 N´m (97 in.
lbs.).
(5) Reconnect the HVAC wire harness connector
for the evaporator temperature sensor to the sensor
connector receptacle on the top of the expansion
valve.
(6) 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.
(7) 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.
(8) Reconnect the liquid line and suction line fit-
tings to the expansion valve.
(9) Install and tighten the nut that secures the
suction line and liquid line fittings to the stud on theexpansion valve. Tighten the nut to 23 N´m (17 ft.
lbs.).
(10) Remove the tape or plugs from the liquid line
rear section fitting for the filter-drier and the filter-
drier outlet port.
(11) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(12) Reconnect the liquid line fitting to the filter-
drier outlet port on the top of the filter-drier.
(13) Install and tighten the screw that secures the
liquid line fitting to the filter-drier. Tighten the screw
to 11 N´m (100 in. lbs.).
(14) 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.
(15) Reconnect the drain tube to the wiper module
drain on the right side of the engine compartment.
(16) Reinstall the air cleaner housing into the
right side of the engine compartment.
(17) Reconnect the battery negative cable.
(18) Evacuate the refrigerant system. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
FRONT/REFRIGERANT - STANDARD PROCE-
DURE - REFRIGERANT SYSTEM EVACUATE).
(19) 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 the
heater 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
24 - 74 PLUMBING - FRONTRS
EXPANSION VALVE (Continued)
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the heater-A/C unit housing is directed through the
heater core.
REMOVAL
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).
(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.
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 - FRONT24-75
HEATER CORE (Continued)
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(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.
(3) Remove the silencer boot fasteners located
around the base of the lower steering shaft from the
dash panel so that it may be pushed aside.
(4) Remove the brake lamp switch from its mount-
ing bracket. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/BRAKE LAMP SWITCH -
REMOVAL).
(5) Disconnect the power brake booster input rod
(push rod) from the pin on the brake pedal arm.
(Refer to 5 - BRAKES - ABS/HYDRAULIC/ME-
CHANICAL/POWER BRAKE BOOSTER - REMOV-
AL).
(6) Remove the three screws that secure the heater
core shield to the left end of the HVAC distribution
housing (Fig. 17).(7) 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.
(8) Remove the heater core shield from the distri-
bution housing.
(9) 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
mop up any spills.
(10) Remove the screw that secures the heater core
tube sealing plate to the heater core supply and
return ports (Fig. 18).
(11) Push both heater core tubes simultaneously
toward the dash panel far enough to disengage their
fittings from the heater core supply and return ports.
(12) Install plugs in, or tape over the opened
heater core tube fittings and both heater core ports.
(13) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
(14) Remove the two screws that secure the heater
core mounting plate to the distribution housing.
(15) While pulling the accelerator pedal upward
(Fig. 19) and pushing the brake pedal downward
(Fig. 20) far enough for clearance, pull the heater
core out of the distribution housing.
(16) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation. Also, if
the heater core was leaking, use absorbent toweling
and reach into the heater core opening to mop up
any residual engine coolant within the distribution
housing.
Fig. 17 Heater Core Shield
1 - HEATER/ AIR CONDITIONER HOUSING
2 - HEATER CORE SHIELD
3 - DISTRIBUTION HOUSING
4 - SCREWS (3)
5 - LOCATION TABS (2)
24 - 76 PLUMBING - FRONTRS
HEATER CORE (Continued)
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