(11) Reconnect the engine wire harness connector
for the compressor clutch coil to the coil wire harness
connector on the top of the compressor.
(12) Reinstall the serpentine accessory drive belt
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION).
(13) Reconnect the battery negative cable.
(14) If a new clutch plate and/or clutch pulley are
being installed, the new clutch components must be
burnished (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/A/C COMPRESSOR CLUTCH
- STANDARD PROCEDURE).
A/C COMPRESSOR CLUTCH
COIL
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL
The air conditioning compressor clutch coil electri-
cal circuit is controlled by the ATC control module
which is integral to the heater-A/C control. Begin
testing of a suspected compressor clutch coil problem
by performing the ATC Function Test using the
DRBIIItscan tool.
A/C HEATER CONTROL
DESCRIPTION
This ATC system uses a combination of electrical
and mechanical controls. These controls provide the
vehicle operator with a number of setting options to
help control the climate and comfort within the vehi-
cle.
The A/C-heater control panel is located on the
instrument panel inboard of the steering column and
below the radio (Fig. 7). The A/C-heater control panel
contains a rotary-type temperature control knob, a
rotary-type mode control knob, a thumbwheel-type
blower motor speed control and an air conditioning
compressor push button switch and indicator lamp.
The A/C-heater control panel also features a push
button switch and indicator lamp for the residual
engine heat utilization (REST) function, cabin heater
or the heater booster (as equipped).
The A/C-heater control panel cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
To control the interior temperature, the A/C-heater
control module uses the actual values from the tem-
perature sensors and the CAN bus and compares
them with the nominal value of the temperature con-
trol switch.The A/C-heater control panel is serviced only as
complete unit and cannot be repaired. If faulty or
damaged, the entire control panel unit must be
replaced.
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) Remove the center bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Remove the two screws that secure the A/C-
heater control to the instrument panel (Fig. 8).
(4) Pull the A/C-heater control away from the
instrument panel far enough to access the connec-
tions on the back of the control.
(5) Mark and disconnect the two control cables
from the A/C-heater control.
Fig. 7 A/C-Heater Control Panel
24 - 12 CONTROLS - FRONTVA
A/C COMPRESSOR CLUTCH (Continued)
INSTALLATION
(1) Connect the wire harness connector to the
blower motor resistor block.
(2) Install the blower motor resistor into the ven-
tilation housing. The housing is indexed to allow
mounting in only one position.
(3) Reconnect the battery negative cable.
BLOWER MOTOR SWITCH
DESCRIPTION
The heater-A/C blower motor is controlled by a
thumbwheel-type blower motor switch, mounted in
the heater-A/C control. The switch allows the selec-
tion of four blower motor speeds with the ignition
switch in the On position.
NOTE: The blower motor will operate only at the
lowest speed when the Residual Engine Heat Utili-
zation (REST) function is selected, regardless of the
blower speed setting on the control panel.
OPERATION
When the ignition is turned to On, the integral
blower motor resistor within the ATC control module
supplies power to the blower motor switch. The
switch directs power to the individual blower driver
circuits through the blower motor resistor block to
the blower motor and then to ground.The blower motor switch cannot be repaired and, if
faulty or damaged, it must be replaced. The switch is
serviced only as a part of the heater-A/C control.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
The blower motor switch can be diagnosed by using
the DRBIIItscan tool. Refer to Body Diagnostic Pro-
cedures. For circuit descriptions and diagrams, refer
to the appropriate wiring information.
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.
The blower motor switch cannot be adjusted or
repaired, and if faulty or damaged, the heater-A/C
control must be replaced (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/A/C HEATER
CONTROL - REMOVAL).
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a two-wire
temperature sensing element located at the coldest
point on the face of the evaporator. The sensor is
attached to the evaporator coil fins. The evaporator
temperature sensor prevents condensation on the
evaporator coil from freezing and obstructing A/C
system air flow. The evaporator temperature sensor
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.
Fig. 12 Blower Motor Resistor Block
1 - BLOWER MOTOR RESISTOR
2 - ELECTRICAL CONNECTOR
3 - VENTILATION HOUSING
VACONTROLS - FRONT 24 - 17
BLOWER MOTOR RESISTOR BLOCK (Continued)
DIAGNOSIS AND TESTING
Before testing the rear blower motor switch, verify
that the front A/C system is functional by performing
the ATC Fuction Test using the DRBIIItscan tool.
Use a volt/ohmmeter to test the rear blower motor
switch. For circuit descriptions and diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
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) Unplug the wire harness connector from the
rear blower motor switch.
(3) Check for continuity between terminal 10 and
terminals 1, 7 and 4 of the blower motor switch. In
all instances, there should be continuity.
NOTE: To check the switch's internal circuits, con-
nect the negative lead of the ohmmeter to terminal
10 and the positive ohmmeter lead to terminals 1, 7
and 4. To check the switch's integral light emitting
diodes, reverse the ohmmeter leads.
(4) Check for continuity between the rear blower
motor switch terminals 3 and 7 as you move the
blower motor switch to each of the two speed posi-
tions, and the Off position. There should be continu-
ity in only one blower motor switch speed position.
(5) Check for continuity between the rear blower
motor switch terminals 4 and 8 as you move the
blower motor switch to each of the two speed posi-
tions, and the Off position. There should be continu-
ity in only the other blower motor switch speed
position.
(6) If OK, test and repair the rear blower motor
switch wire harness circuits. If not OK, replace the
faulty rear blower motor switch.
REMOVAL
NOTE: The rear blower motor switch is used only
on models with the optional rear A/C unit.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the blower motor switch from the
switch panel.
(3) Disconnect the wire harness connector from the
rear blower motor switch and remove the switch from
the vehicle.
INSTALLATION
(1) Connect the wire harness connector to the rear
blower motor switch.
(2) Install the blower motor switch into the switch
panel.
(3) Reconnect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relays are an International Stan-
dards Organization (ISO)-type relay. The relays are
electro-mechanical devices which when energized,
directs fused battery current to the rear blower
motor. The relay coils are energized when they
receives a voltage signal from the blower motor
switch.
OPERATION
When the rear blower motor switch is in the low
speed position, the switch directs a voltage signal to
the high side of rear blower relay #1 and energizes
its relay coil. When energized, the low side of blower
relay #1 directs fused battery current through an
integral blower resistor to the rear blower motor.
When in the high speed position, the rear blower
switch directs a voltage signal to the high side of
rear blower relay #2 and energizes its relay coil.
When energized, the low side of blower relay #2
directs fused battery current through an integral
blower resistor to the rear blower motor.
The rear blower motor relays are located in the
relay block of the rear evaporator housing. Refer to
the appropriate wiring diagrams for more informa-
tion.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
VACONTROLS - REAR 24 - 23
BLOWER MOTOR SWITCH (Continued)
CAUTION
CAUTION
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. Damage to the system will result.
R-12 refrigerant oil must not be mixed with R-134a
refrigerant oil. They are not compatible.
Do not use R-12 equipment or parts on the R-134a
system. Damage to the system will result.
Do not overcharge the refrigerant system. This 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.
The refrigerant system must always be evacuated
before charging.
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 out-
side of the fittings thoroughly to prevent contami-
nation from entering the refrigerant system.
Immediately after disconnecting a component from
the refrigerant system, seal the open fittings with a
cap or plug.
Before connecting an open refrigerant fitting,
always install a new seal or gasket. Coat the fitting
and seal with clean refrigerant oil before connect-
ing.
Do not remove the sealing caps from a replacement
component until it is to be installed.
When installing a refrigerant line, avoid sharp
bends that may restrict refrigerant flow. Position the
refrigerant lines away from exhaust system compo-
nents or any sharp edges, which may damage the
line.
Tighten refrigerant fittings only to the specified
torque. The aluminum fittings used in the refriger-
ant system will not tolerate overtightening.
When disconnecting a refrigerant fitting, use a
wrench on both halves of the fitting. This will pre-
vent twisting of the refrigerant lines or tubes.
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 through care-
less work habits must be avoided.REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS
Kinks or sharp bends in the refrigerant plumbing
will reduce the capacity of the entire system. High
pressures are produced in the system when it is oper-
ating. Extreme care must be exercised to make sure
that all refrigerant system connections are pressure
tight.
A good rule for the flexible hose refrigerant lines is
to keep the radius of all bends at least ten times the
diameter of the hose. Sharp bends will reduce the
flow of refrigerant. The flexible hose lines should be
routed so they are at least 80 millimeters (3 inches)
from the exhaust manifold. It is a good practice to
inspect all flexible refrigerant system hose lines at
least once a year to make sure they are in good con-
dition and properly routed.
There are two types of refrigerant fittings:
²All fittings with O-rings need to be coated with
refrigerant oil before installation. Use only O-rings
that are the correct size and approved for use with
R-134a refrigerant. Failure to do so may result in a
leak.
²Unified plumbing connections with gaskets can-
not be serviced with O-rings. The gaskets are not
reusable and new gaskets do not require lubrication
before installing.
Using the proper tools when making a refrigerant
plumbing connection is very important. Improper
tools or improper use of the tools can damage the
refrigerant fittings. Always use two wrenches when
loosening or tightening tube fittings. Use one wrench
to hold one side of the connection stationary, while
loosening or tightening the other side of the connec-
tion with a second wrench.
The refrigerant must be recovered completely from
the system before opening any fitting or connection.
Open the fittings with caution, even after the refrig-
erant has been recovered. If any pressure is noticed
as a fitting is loosened, tighten the fitting and
recover the refrigerant from the system again.
Do not discharge refrigerant into the atmosphere.
Use an R-134a refrigerant recovery/recycling device
that meets SAE Standard J2210.
The refrigerant system will remain chemically sta-
ble as long as pure, moisture-free R-134a refrigerant
and refrigerant oil is used. Dirt, moisture, or air can
upset this chemical stability. Operational troubles or
serious damage can occur if foreign material is
present in the refrigerant system.
VAPLUMBING 24 - 45
PLUMBING (Continued)
²If a single probe is used, record the temperature
of the evaporator inlet tube. Then remove the probe
from the inlet tube and attach it to the evaporator
outlet tube just before the collar of the refrigerant
line connector fitting. The probe must make contact
with the bottom surface of the evaporator outlet tube.
Allow the thermocouple and meter time to stabilize,
then record the temperature of the evaporator outlet
tube. Subtract the inlet tube temperature reading
from the outlet tube temperature reading.
²If dual probes are used, record the temperatures
of both the evaporator inlet and outlet tubes. Then
subtract the inlet tube temperature reading from the
outlet tube temperature reading.(9) If the measured temperature differential is
higher than 22É C to 26É C (40É F to 47É F), add 0.4
kilograms (14 ounces) of refrigerant.
(10) Allow three to five minutes for the refrigerant
system to stabilize, then take a second set of thermo-
couple measurements. Record the temperature differ-
ence to determine if an additional charge is required.
(11) Record the compressor discharge pressure. If
the reading is higher than the pressure shown in the
Compressor Discharge Pressure Chart, the system
could be overcharged. If the reading is equal to, or
lower, than the pressure shown in the chart, continue
with this procedure.
Compressor Discharge Pressure Chart
Ambient
Temperature16ÉC
(60ÉF)21ÉC
(70ÉF)27ÉC
(80ÉF)32ÉC
(90ÉF)38ÉC
(100ÉF)43ÉC
(110ÉF)
Compressor
Discharge
Pressure1378 kPa
(200 psi)1516 kPa
(220 psi)1723 kPa
(250psi)1930 kPa
(280 psi)2206 kPa
(320 psi)2413 kPa
(350 psi)
(12)EXAMPLE:The ambient temperature is 21É
C (70É F). The evaporator inlet tube temperature is
12É C (54É F) and the evaporator outlet tube temper-
ature is 10É C (50É F). Subtract the inlet tube tem-
perature from the outlet tube temperature. The
difference is -2É C (-4É F). With a -2É C (-4É F) tem-
perature differential at 21É C (70É F) ambient tem-
perature, the system is fully charged.
(13) Add enough refrigerant to bring the refriger-
ant system up to a full charge.
(14) Remove the jumper wire from the low pres-
sure cycling clutch switch wire harness connector
and plug the connector back into the switch.
SPECIFICATIONS
CHARGE CAPACITY
Always refer to the underhood HVAC Specification
Tag for the latest fill specification for the model being
serviced.
A/C COMPRESSOR
DESCRIPTION
The air conditioning system uses a Nippondenso
7SBU16C double-acting, variable swash plate-type
compressor on all models. This compressor has a
label identifying the use of R-134a refrigerant and
both the suction and discharge ports located on the
cylinder head.
OPERATION
The compressor is driven by the engine through an
electric clutch, drive pulley and belt arrangement.
The compressor is lubricated by refrigerant oil that is
circulated throughout the refrigerant system with the
refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley, and coil, are
available for service.
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
VAPLUMBING 24 - 49
PLUMBING (Continued)
(6) Connect the discharge line fitting to the com-
pressor discharge port.
(7) Install the bolt that secures the discharge line
fitting to the top of the compressor. Tighten the bolt
to 23 N´m (17 ft. lbs.).
(8) Remove plugs or tape from the suction line fit-
ting and the compressor suction port.
(9) Lubricate a new rubber o-ring seal with clean
refrigerant oil and install the seal onto the suction
line fitting.
(10) Connect the suction line fitting to the com-
pressor suction port.
(11) Install the bolt that secures the suction line
fitting to the top of the compressor. Tighten the bolt
to 23 N´m (17 ft. lbs.).
(12) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(13) Reconnect the negative battery cable.
(14) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(15) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
A/C CONDENSER
DESCRIPTION
The condenser is located in the air flow in front of
the engine cooling radiator. The condenser is a heat
exchanger that allows the high-pressure refrigerant
gas being discharged by the compressor to give up its
heat to the air passing over the condenser fins.
OPERATION
When the refrigerant gas gives up its heat, it con-
denses. When the refrigerant leaves the condenser, it
has become a high-pressure liquid refrigerant. The
volume of air flowing over the condenser fins is crit-
ical to the proper cooling performance of the air con-
ditioning system. Therefore, it is important that
there are no objects placed in front of the radiator
grille openings in the front of the vehicle or foreign
material on the condenser fins that might obstruct
proper air flow. Also, any factory-installed air seals or
shrouds must be properly reinstalled following radia-
tor or condenser service.
The condenser cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
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).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the front fascia.
(4) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(5) Remove the headlamps from their mounts.
(6) Remove the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(7) Disconnect the liquid line fitting from the con-
denser outlet port (Fig. 3).
(8) Remove the seal from the liquid line fitting and
discard.
(9) Install plug in, or tape over the opened liquid
line fitting and the condenser outlet port.
(10) Disconnect the discharge line fitting from the
condenser inlet port.
(11) Remove the seal from the discharge line fit-
ting and discard.
(12) Install plug in, or tape over the opened dis-
charge line fitting and the condenser inlet port.
(13) Disconnect the wire harness connector from
the auxiliary fan.
(14) Remove the auxiliary fan and upper bracket
assembly.
(15) Remove the auxiliary fan lower bracket
retainers and bracket.
(16) Remove the four condenser retaining screws.
(17) Carefully remove the condenser from the vehi-
cle.
INSTALLATION
NOTE: If the condenser is being replaced, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Carefully position the condenser in the vehicle.
(2) Install the four condenser retaining screws.
Tighten the screws to 2 N´m (17 in. lbs.).
24 - 52 PLUMBINGVA
A/C COMPRESSOR (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.
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).
(1) Remove the heater housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the heater housing to access the
evaporator (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HVAC HOUSING - DIS-
ASSEMBLY).
(3) Lift the evaporator out of the lower half of the
heater housing (Fig. 5).
INSTALLATION
(1) Install the evaporator coil into the bottom half
of the heater housing.
(2) Assemble the heater housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the heater housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
NOTE: If the evaporator is being replaced, add 60
milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system.
A/C EXPANSION VALVE
DESCRIPTION
The ªHº valve type thermal expansion valve (TXV)
is mounted in the engine compartment between the
liquid and suction lines and the evaporator.
The expansion valve is a factory calibrated unit
and cannot be adjusted or repaired. If faulty or dam-
aged, the expansion valve must be replaced.
OPERATION
High-pressure, high 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 thermal sensor in the
expansion valve monitors the temperature 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 to meet the vehicle cooling requirements.
Controlling the refrigerant flow through the evapora-
Fig. 5 Heater Housing
1 - SCREW (12)
2 - HEATER HOUSING COVER
3 - EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
4 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - HEATER HOUSING
8 - WIRING HARNESS
9 - BOLT (3)
10 - HEATER CORE
11 - HEATER CORE TUBE ASSEMBLY
12 - HEATER CORE TUBE GASKET
13 - HEATER CORE TUBE O-RING SEAL (2)
VAPLUMBING 24 - 55
A/C EVAPORATOR (Continued)
RECEIVER/DRIER
DESCRIPTION
The receiver/drier is mounted in a bracket secured
to the left front strut tower in the engine compart-
ment. The receiver/drier is connected between the
front and rear sections of the liquid line between the
condenser outlet and the evaporator inlet. The receiv-
er/drier cannot be repaired. If the receiver/drier is
faulty or damaged, or if the refrigerant system has
been contaminated or left open to the atmosphere for
an indeterminable period or if the compressor has
failed, it must be replaced.
OPERATION
The receiver/drier performs a filtering action to
prevent foreign material in the refrigerant from con-
taminating the expansion valve. A desiccant bag is
mounted inside the receiver/drier canister to absorb
any moisture which may have entered and become
trapped within the refrigerant system. In addition,
during periods of high demand air conditioner opera-
tion, the receiver/drier acts as a reservoir to store
surplus refrigerant. Refrigerant enters the receiver/
drier as a high-pressure, low-temperature liquid.
REMOVAL
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).
(1) Recover the refrigerant from the refrigerant
system(Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE).
(2) Remove the bolts that secure the front and rear
sections of the liquid line to the top of the receiver/
drier (Fig. 15).
(3) Disconnect the liquid line fittings from the
receiver/drier.
(4) Remove the seals from the liquid line fittings
and discard.
(5) Install a plug in, or tape over the opened liquid
line fittings and the receiver/drier ports.
(6) Loosen the clamp that secures the receiver/
drier to the mounting bracket.
(7) Remove the receiver/drier from the engine com-
partment.
INSTALLATION
NOTE: If the receiver/drier is being replaced, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the
type recommended for the compressor in the vehi-
cle.
(1) Position the receiver/drier onto the mounting
bracket on the front left strut tower.
(2) Tighten the clamp that secures the receiver/
drier to the mounting bracket.
(3) Remove the tape or plugs from the liquid line
fittings and the receiver/drier ports.
(4) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the liquid line fit-
tings.
(5) Connect the front and rear sections of the liq-
uid line to the receiver/drier.
(6) Install the bolts that secures the liquid line fit-
tings to the receiver/drier. Tighten the bolts to 7 N´m
(62 in. lbs.).
(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).
Fig. 15 Receiver/Drier
1 - RECEIVER/DRIER
2 - LIQUID LINE (REAR SECTION)
3 - A/C PRESSURE TRANSDUCER
4 - LIQUID LINE (FRONT SECTION)
5 - CLAMP
24 - 64 PLUMBINGVA