INSTALLATION
(1) Position the rear blower motor resistor block
into the rear HVAC housing.
(2) Install the two screws that secure the rear
blower motor resistor block to the rear HVAC hous-
ing. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Connect the rear HVAC wire harness connector
to the rear blower motor resistor block.
(4) 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).
(5) Reconnect the battery negative cable.
MODE DOOR ACTUATOR -
REAR
DESCRIPTION
The rear mode door actuator is a reversible, 12-volt
Direct Current (DC), servo motor. The mode door
actuator is located on the outboard side of the rear
HVAC housing, above the blend door actuator. The
mode door actuator is mechanically connected to the
mode door.
The rear mode door actuator is interchangeable
with the actuator for the blend door. Each actuator is
contained within an identical black molded plastic
housing with an integral wire connector receptacle.
Two integral mounting tabs allow the actuator to be
secured with two screws to the rear HVAC housing.
Each actuator also has an identical output shaft with
splines that connects it to the pivot or linkage of the
proper door. The rear mode door actuator does not
require mechanical indexing to the mode door pivot,
as it is electronically calibrated by the front heater-
A/C control module.
OPERATION
The rear mode door actuator is connected to the
front heater-A/C control module through the vehicle
electrical system by a dedicated two-wire take out
and connector of the rear HVAC wire harness. The
rear mode door actuator can move the mode door in
two directions. When the front heater-A/C control
module pulls the voltage on one side of the motor
connection high and the other connection low, the
rear mode door will move in one direction. When themodule reverses the polarity of the voltage to the
motor, the rear mode door moves in the opposite
direction. When the module makes the voltage to
both connections high or both connections low, the
mode door stops and will not move. These same
motor connections also provide a feedback signal to
the front heater-A/C control module. This feedback
signal allows the module to monitor the operation
and relative positions of the rear mode door actuator
and the mode door. The front heater-A/C control mod-
ule learns the rear mode door stop positions during
the calibration procedure and will store a Diagnostic
Trouble Code (DTC) for any problems it detects in
the mode door actuator circuits.
The rear mode door actuator can be diagnosed
using a DRBIIItscan tool. Refer to Body Diagnostic
Procedures for more information. The rear mode door
actuator cannot be adjusted or repaired and, if dam-
aged or faulty, it must be replaced.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the right quarter trim panel and right
D-pillar trim panel from the quarter inner panel
(Refer to 23 - BODY/INTERIOR/QUARTER TRIM
PANEL - REMOVAL).
(3) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.
(4) Remove the screw that secures the back of the
rear HVAC housing to the right D-pillar.
(5) Remove the screw that secures the front of the
rear HVAC housing to the right quarter inner panel.
(6) Carefully pull the top of the rear HVAC hous-
ing away from the right quarter inner panel far
enough to reach between the rear HVAC housing and
the quarter inner panel to access the rear mode door
actuator (Fig. 7).
(7) Remove the two screws that secure the mode
door actuator to the rear HVAC housing.
(8) Pull the mode door actuator away from the
rear HVAC housing far enough to disengage the
actuator output shaft from the mode door linkage.
(9) Raise the mode door actuator far enough to
access and disconnect the rear HVAC wire harness
connector from the actuator
RSCONTROLS - REAR24-39
BLOWER MOTOR RESISTOR BLOCK (Continued)
INSTRUMENT PANEL OUTLETS
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the outer perimeter of the
instrument panel outlet away from the instrument
panel top pad until the snap features on the outlet
are released (Fig. 5).
(2) Remove the instrument panel outlet from the
panel duct opening in the instrument panel top pad.
INSTALLATION
FRONT CENTER BEZEL OUTLETS
(1) Position the center bezel outlets and housing
onto the center bezel as a unit.
(2) Engage the retainer features on the top of the
outlet housing with their receptacles at the top of the
center bezel, then roll the bottom of the outlet hous-
ing downwards towards the center bezel.
(3) Install the three screws that secure the bottom
of the outlet housing to the center bezel. Tighten the
screws to 2 N´m (17 in. lbs.).
(4) If the vehicle is equipped with the optional
ATC system, reconnect the ATC remote infrared tem-
perature sensor jumper harness to the sensor connec-
tor receptacle located on the bottom of the center
outlet housing.
(5) Reinstall the center bezel onto the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(6) Reconnect the battery negative cable.
FRONT DEMISTER OUTLETS
(1) Position the demister outlet over the demister
duct opening in the instrument panel top pad.(2) Using hand pressure, press the demister outlet
firmly and evenly into the instrument panel top pad
opening until the snap features on the outlet are
fully engaged.
INSTRUMENT PANEL OUTLETS
(1) Position the instrument panel outlet into the
panel duct opening in the instrument panel top pad.
(2) Using hand pressure, press the instrument
panel outlet firmly and evenly into the instrument
panel top pad opening until the snap features on the
outlet are fully engaged.
BLOWER MOTOR
DESCRIPTION
The blower motor is a 12-volt, Direct Current (DC)
motor with a squirrel cage-type blower wheel that is
secured to the blower motor shaft (Fig. 6). The
blower motor and wheel are located near the passen-
ger side end of the HVAC housing in the passenger
compartment below the instrument panel. The
blower motor and blower motor wheel are factory bal-
anced and cannot be adjusted or repaired. If faulty or
damaged, the blower motor and blower wheel must
be replaced as an assembly.
OPERATION
On models equipped with the manual heater-A/C
system, the blower motor will operate whenever the
ignition switch is in the On position and the blower
control switch is in any position except Off. On mod-
els equipped with the Automatic Temperature Con-
trol (ATC) system, the blower motor will operate
Fig. 5 Instrument Panel Outlet - Left Side Shown
1 - INSTRUMENT PANEL TOP PAD
2 - INSTRUMENT PANEL OUTLET
3 - TRIM STICK
Fig. 6 Blower Motor
1 - BLOWER MOTOR
2 - RUBBER GROMMET
3 - BLOWER MOTOR CONNECTOR
4 - MOUNTING TABS
RSDISTRIBUTION - FRONT24-45
AIR OUTLETS (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)
(13) Remove the two screws that secure the top of
the quarter trim panel attaching bracket to the quar-
ter inner panel.(14) Remove the two screws that secure the bottom
of the quarter trim panel attaching bracket to the
rear HVAC housing.
(15) Remove the rear floor heat duct from the
right quarter inner panel (Refer to 24 - HEATING &
AIR CONDITIONING/DISTRIBUTION/REAR
FLOOR HEAT DUCT - REMOVAL).
(16) Take the proper precautions to protect the
carpeting below the rear heater core from spilled
engine coolant and have absorbent toweling readily
available to clean up any spills.
(17) Disconnect the heater hoses at the rear heater
core (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - REAR/HEATER HOSE -
REMOVAL).
(18) Install plugs in, or tape over the opened
heater core fittings and both heater hoses.
(19) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
(20) Remove the screw that secures the back of the
rear HVAC housing to the right D-pillar (Fig. 8).
(21) Remove the screw that secures the front of
the rear HVAC housing to the right quarter inner
panel.
(22) Lift the rear HVAC housing up far enough for
the lower mounting studs and the evaporator exten-
sion lines to clear the mounting holes in the rear
floor panel.
(23) Remove the rear HVAC housing from the
vehicle.
(24) Use absorbent toweling to mop up any engine
coolant spills from the preceding operation.
Fig. 5 Underbody A/C Line Rear Connections ± with
New Seating Element (NSE)
1 - UNDERBODY LIQUID LINE
2 - NUT
3 - SEALING PLATE
4 - UNDERBODY SUCTION LINE
5 - EXTENSION LINE TAPPING PLATE
Fig. 6 Underbody A/C Line Rear Connections ±
without New Seating Element (NSE)
1 - UNDERBODY LIQUID LINE
2 - BOLT
3 - EXTENSION LINE TAPPING PLATE
4 - UNDERBODY SUCTION LINE
5 - SEALING PLATE
Fig. 7 Rear HVAC Housing Mounting Studs ±
Typical
1 - REAR HVAC HOUSING MOUNTING STUDS
RSDISTRIBUTION - REAR24-61
HVAC HOUSING (Continued)
A/C SYSTEM
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.
AVOID BREATHING THE REFRIGERANT AND
REFRIGERANT OIL VAPOR OR MIST. EXPOSURE
MAY IRRITATE THE EYES, NOSE, AND/OR THROAT.
WEAR EYE PROTECTION WHEN SERVICING THE
AIR CONDITIONING REFRIGERANT SYSTEM. SERI-
OUS EYE INJURY CAN RESULT FROM DIRECT
CONTACT WITH THE REFRIGERANT. IF EYE CON-
TACT OCCURS, SEEK MEDICAL ATTENTION IMME-
DIATELY.
DO NOT EXPOSE THE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC LEAK
DETECTOR IS RECOMMENDED.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE THE WORK AREA BEFORE RESUMING
SERVICE. LARGE AMOUNTS OF REFRIGERANT
RELEASED IN A CLOSED WORK AREA WILL DIS-
PLACE THE OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF R-134a REFRIGER-
ANT AT AVERAGE TEMPERATURE AND ALTITUDE
IS EXTREMELY HIGH. AS A RESULT, ANYTHING
THAT COMES IN CONTACT WITH THE REFRIGER-
ANT WILL FREEZE. ALWAYS PROTECT THE SKIN
OR DELICATE OBJECTS FROM DIRECT CONTACT
WITH THE REFRIGERANT.
THE R-134a SERVICE EQUIPMENT OR THE VEHI-
CLE REFRIGERANT SYSTEM SHOULD NOT BE
PRESSURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR. SOME MIXTURES OF AIR AND
R-134a HAVE BEEN SHOWN TO BE COMBUSTIBLE
AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS, AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROP-
ERTY DAMAGE.
CAUTION - A/C SYSTEM
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with the service equipment being used.
Never add R-12 to a refrigerant system designed to
use R-134a and do not use R-12 equipment or parts
on the R-134a system. Damage to the system will
result.
R-12 refrigerant oil must not be mixed with R-134a
refrigerant oil. They are not compatible and damage
to the system will result.Do not overcharge the refrigerant system. Over-
charging will cause excessive compressor head
pressure and can cause noise and system failure.
Recover the refrigerant before opening any fitting
or connection. Open the fittings with caution, even
after the system has been discharged. Never open
or loosen a connection before recovering the refrig-
erant.
If equipped, do not remove the secondary retention
clip from any spring-lock coupler connection while
the refrigerant system is under pressure. Recover
the refrigerant before removing the secondary
retention clip. Open the fittings with caution, even
after the system has been discharged. Never open
or loosen a connection before recovering the refrig-
erant.
Do not open the refrigerant system or uncap a
replacement component until you are ready to ser-
vice the system. This will prevent contamination in
the system. Before disconnecting a component,
clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system. Immediately after disconnecting a compo-
nent from the refrigerant system, seal the open fit-
tings with a cap or plug.
Refrigerant oil will absorb moisture from the atmo-
sphere if left uncapped. Do not open a container of
refrigerant oil until you are ready to use it. Replace
the cap on the oil container immediately after using.
Store refrigerant oil only in a clean, airtight, and
moisture-free container.
Keep service tools and the work area clean. Con-
tamination of the refrigerant system must be
avoided.
CAUTION: The use of A/C system sealers may
result in damage to A/C refrigerant recovery/evacu-
ation/recharging equipment and/or A/C systems.
Many federal, state/provincial and local regulations
prohibit the recharge of A/C systems with known
leaks. DaimlerChrysler recommends the detection
of A/C system leaks through the use of approved
leak detectors and fluorescent leak detection dyes.
Vehicles found with A/C system sealers should be
treated as contaminated and replacement of the
entire A/C refrigerant system is recommended. A/C
systems found to be contaminated with A/C system
sealers, A/C stop-leak products or seal conditioners
voids the warranty for the A/C system.
24 - 66 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)
(4) Raise the liquid line (discharge) pressure to
about 1793 kPa (260 psi) by placing a piece of card-
board over part of the front side of the condenser. To
place the cardboard properly, remove the upper radi-
ator sight shield from the front fascia. Cover only
enough of the condenser to raise and maintain the
liquid line pressure at the specified level.
(5) Observe the liquid line (discharge) pressure
and liquid line temperature. Using the Charge Deter-
mination Chart (Fig. 1), determine whether the
refrigerant system is operating within the Proper
Charge Range.
(a) If the refrigerant system is operating in the
Undercharged area of the chart, add 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant to
the system.
(b) If the refrigerant system is operating in the
Overcharged area of the chart, reclaim 0.057 kilo-
gram (0.125 pound or 2 ounces) of refrigerant from
the system.
(6) Recheck the system charge level following each
refrigerant adjustment. Continue this process until
the system readings are in the Proper Charge Range
area on the Charge Determination Chart.
STANDARD PROCEDURE
HANDLING TUBING AND FITTINGS
CAUTION: The system must be completely empty
before opening any fitting or connection in the
refrigeration system. Open fittings with caution
even after the system has been emptied. If any
pressure is noticed as a fitting is loosened,
retighten fitting and evacuate the system again.
A good rule for the flexible hose lines is to keep the
radius of all bends at least 10 times the diameter of
the hose. Sharper bends will reduce the flow of
refrigerant. The flexible hose lines should be routed
so they are at least 3 inches (80 mm) from the
exhaust manifold. Inspect all flexible hose lines to
make sure they are in good condition and properly
routed.
The use of correct wrenches when making connec-
tions is very important. Improper wrenches or
improper use of wrenches can damage the fittings.
The internal parts of the A/C system will remain sta-
ble as long as moisture-free refrigerant and refrig-
erant oil is used. Abnormal amounts of dirt,
moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities. Before disconnecting a component,
clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system.When opening a refrigeration system, have every-
thing you will need to repair the system ready. This
will minimize the amount of time the system must
be opened. Cap or plug all lines and fittings as
soon as they are opened. This will help prevent the
entrance of dirt and moisture. All new lines and
components should be capped or sealed until they
are ready to be used. Before connecting a compo-
nent, clean the outside of the fittings thoroughly to
prevent contamination from entering the refrigerant
system.
All tools, including the refrigerant dispensing mani-
fold, the manifold gauge set, and test hoses should
be kept clean and dry.
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are pro-
duced in the system when it is operating. Extreme
care must be exercised to make sure that all connec-
tions are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replace-
ment of lines or components. The refrigerant oil will
absorb moisture readily out of the air. This moisture
will convert into acids within a closed system.
REFRIGERANT SYSTEM SERVICE EQUIPMENT
WARNING: EYE PROTECTION MUST BE WORN
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE CONNECTING TO, OR DISCONNECTING
FROM THE REFRIGERANT SYSTEM. FAILURE TO
OBSERVE THESE WARNINGS MAY RESULT IN PER-
SONAL INJURY.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
RECOVERY/RECYCLING STATION
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SEA Standard J2210 must be used
(Fig. 2). Contact an automotive service equipment
supplier for refrigerant recovery/recycling/charging
equipment. See the operating instructions supplied
by the equipment manufacturer for proper care and
use of this equipment.
RSPLUMBING - FRONT24-69
PLUMBING - FRONT (Continued)
INSTALLATION
(1) Position the A/C discharge line into the engine
compartment.
(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 and a new gasket onto
the discharge line fitting.
(4) Install the A/C discharge line to the A/C com-
pressor.(5) Install the nut that secures the A/C discharge
line to the A/C 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 and a new gasket onto
the discharge line fitting.
(8) Install the A/C discharge line to the A/C con-
denser.
(9) Install the nut that secures the A/C discharge
line to the A/C 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 the five small screws that secure the
front fascia grille inserts to the radiator sight shield.
Tighten the screws to 2 N´m (17 in. lbs.).
(12) Install the two large screws that secure the
front fascia and the outboard ends of the radiator
sight shield to the radiator closure panel crossmem-
ber. 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).
A/C EVAPORATOR
DESCRIPTION
The A/C evaporator is located in the HVAC hous-
ing, behind the instrument panel. The evaporator is
positioned in the housing so that all air that enters
the housing must pass over the fins of the evaporator
coils 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 through the
evaporator tubes.
OPERATION
Refrigerant enters the A/C evaporator from the
expansion valve as a low-temperature, low-pressure
liquid. As air flows over the fins of the evaporator,
the humidity in the air condenses on the fins, and
the heat from the air is absorbed by the refrigerant.
Heat absorption causes the refrigerant to boil and
vaporize. The refrigerant becomes a low-pressure gas
when it leaves the evaporator.
The A/C evaporator cannot be repaired and, if
faulty or damaged, it must be replaced.
Fig. 13 A/C Discharge Line to A/C Condenser -
Typical
1 - A/C CONDENSER
2 - A/C DISCHARGE LINE
3 - A/C LIQUID LINE
4 - NUT (2)
Fig. 14 A/C Discharge Line to Compressor - Typical
1 - DISCHARGE LINE
2 - NUT
3 - DISCHARGE LINE FITTING
4 - STUD
5 - DISCHARGE PORT
24 - 80 PLUMBING - FRONTRS
A/C DISCHARGE LINE (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)