Oil pan DODGE RAM 1500 1998 2.G Workshop Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 1998, Model line: RAM 1500, Model: DODGE RAM 1500 1998 2.GPages: 2627
Page 2300 of 2627

CODE FAMILY NAME COMMON TRADE NAME TYPICAL APPLICATION
PC/ABS PC/ABS ALLOY GERMAX, BAY BLENDS,
PULSEDOORS, INSTRUMENT
PANELS
PPO POLYPHENYLENE OXIDE AZDEL, HOSTALEN,
MARLEX, PRFAX, NORYL,
GTX, PPOINTERIOR TRIM, DOOR
PANELS, SPLASH SHIELDS,
STEERING COLUMN
SHROUD
PPO/PA POLYPHENYLENE/
POLYAMIDPPO/PA, GTX 910 FENDERS, QUARTER
PANELS
PR/FV FIBERGLASS REINFORCED
PLASTICFIBERGLASS, FV, PR/FV BODY PANELS
PS POLYSTYRENE LUSTREX, STYRON, PS DOOR PANELS, DASH
PANELS
RTM RESIN TRANSFER
MOLDING COMPOUNDRTM BODY PANELS
SMC SHEET MOLDED
COMPOUNDSMC BODY PANELS
TMC TRANSFER MOLDING
COMPOUNDTMC GRILLES
UP UNSATURATED
POLYESTER
(THERMOSETTING)SMC, BMC, TMC, ZMC, IMC,
XSMC, UPGRILLE OPENING PANEL,
LIFTGATES, FLARESIDE
FENDERS, FENDER
EXTENSIONS
EEBC ETHER/ESTER BLOCKED
CO-POLYMEREEBC BUMPERS
EEBC/PBTP EEBC/POLYBUTYLENE
TEREPTHALATEEEBC, PBTP, BEXLOY BUMPER, ROCKER PANELS
EMPP ETHYLENE MODIFIED
POLYPROPYLENEEMPP BUMPER COVERS
EPDM ETHYLENE/
PROPROPYLENE DIENE
MONOMEREPDM, NORDEL, VISTALON BUMPERS
EPM ETHYLENE/
PROPROPYLENE CO-
POLYMEREPM FENDERS
MPU FOAM POLYURETHANE MPU SPOILERS
PE POLYETHYLENE ALATHON, DYLAN,
LUPOLEN, MARLEX-
PP POLYPROPYLENE
(BLENDS)NORYL, AZDEL, MARLOX,
DYLON, PRAVEXINNER FENDER, SPOILERS,
KICK PANELS
PP/EPDM PP/EPDM ALLOY PP/EPDM SPOILERS, GRILLES
PUR POLYURETHANE COLONELS, PUR, PU FASCIAS, BUMPERS
PUR/PC PUR/PC ALLOY TEXIN BUMPERS
PVC POLYVINYL CHLORIDE APEX, GEON, VINYLITE BODY MOLDINGS, WIRE
INSULATION, STEERING
WHEELS
RIM REACTION INJECTED
MOLDED POLYURETHANERIM, BAYFLEX FRONT FASCIAS, MODULAR
WINDOWS
DRBODY 23 - 5
BODY (Continued)
Page 2303 of 2627

should be stripped of paint and freed from wax and
oil. Scuff surfaces around repair area with 360 grit
wet/dry sandpaper, or equivalent, to assure adhesion
of repair materials.
PATCHING PANELS
An panel that has extensive puncture type damage
can be repaired by cutting out the damaged material
(Fig. 7). Use a suitable reciprocating saw or cut off
wheel to remove the section of the panel that is dam-
aged. The piece cut out can be used as a template to
shape the new patch. It is not necessary to have
access to the back of the panel to install a patch.
Bevel edges of cutout at 20 degrees to expose a larger
bonding area on the outer side. This will allow for an
increased reinforcement areas.
PANEL PATCH FABRICATIONS
A patch can be fabricated from any rigid fiberglass
panel that has comparable contour with the repair
area. Lift gates and fenders can be used to supply
patch material. If existing material is not available
or compatible, a patch can be constructed with adhe-
sive and reinforcement mesh (dry wall tape). Perform
the following operation if required:
(1) Cover waxed paper or plastic with adhesive
backed nylon mesh (dry wall tape) larger than the
patch required (Fig. 8).(2) Tape waxed paper or plastic sheet with mesh to
a surface that has a compatible contour to the repair
area.
(3) Apply a liberal coat of adhesive over the rein-
forcement mesh (Fig. 8). If necessary apply a second
or third coat of adhesive and mesh after first coat
has cured. The thickness of the patch should be the
same as the repair area.
(4) After patch has cured, peel waxed paper or
plastic from the back of the patch.
(5) If desired, a thin film coat of adhesive can be
applied to the back of the patch to cover mesh for
added strength.
PANEL PATCH INSTALLATION
(1) Make a paper or cardboard pattern the size
and shape of the cutout hole in the panel.
(2) Trim 3 mm (0.125 in.) from edges of pattern so
patch will have a gap between connecting surfaces.
(3) Using the pattern as a guide, cut the patch to
size.
(4) Cut scrap pieces of patch material into 50 mm
(2 in.) squares to use as patch supports to sustain
the patch in the cutout.
(5) Drill 4 mm (0.160 in.) holes 13 mm (0.5 in.) in
from edge of cutout hole (Fig. 7).
(6) Drill 4 mm (0.160 in.) holes 13 mm (0.5 in.)
away from edge of patch across from holes drilled
around cutout.
Fig. 7 DAMAGED PANEL CUTOUT AND PATCH
1 - CUTOUT
2 - DAMAGED BODY PANEL
3-4MM(0.160 IN.) HOLES
4 - PATCH CUT TO SIZE
Fig. 8 FABRICATED PANEL
1 - STRUCTURAL ADHESIVE
2 - FIBERGLASS CLOTH OR FIBERGLASS MESH TAPE
3 - WIDTH OF V-GROOVE
4 - WAXED PAPER
23 - 8 BODYDR
BODY (Continued)
Page 2306 of 2627

STANDARD PROCEDURE - BUZZ, SQUEAK &
RATTLE
Buzz, Squeak & Rattles (BSR) may be caused by
any one or more of the following and may be cor-
rected as indicated:
²Loose fasteners should be tightened to specifica-
tions.
²Damaged or missing clips should be replaced.
²Damaged trim panels should be replaced.²Incorrectly installed trim panels should be rein-
stalled properly.
Many BSR complaints such as loose trim, can be
serviced using the MopartParts BSR Noise Reduc-
tion Kit. This kit contains various tapes including
foam, flock and anti-squeak used to eliminate noises
caused by metal, plastic and vinyl components. Long
life lubricants and greases can also be used on a vari-
ety of components. Refer to the Buzz, Squeak & Rat-
tle Kit table for material contents and usage.
BUZZ, SQUEAK & RATTLE KIT
ITEM FEATURES APPLICATIONS SERVICE TEMP
Itch And Squeak
TapeAn abrasion resistant material
thin enough to conform to most
irregular surfaces. Stops most
itches and squeaks.Between metal and metal,
metal and plastic, metal and
vinyl, vinyl and plastic. Interior.
Examples: Trim panels and
bezels.-40É to 225É
Fahrenheit
(-40É to 107É
Celsius)
Black Nylon Flock Nylon Flock with an aggressive
acrylic adhesive. Provides for
cushioning and compression fit,
also isolates components.
Water-resistant.Between metal and metal,
metal and plastic, vinyl and
plastic.
Examples: Pull cups, bezels,
clips, ducts, top cover to glass,
cowl panel.-40É to 180É
Fahrenheit
(-40É to 82É Celsius)
High Density
Urethane FoamTear resistant, highly resilient
and durable.Between metal and metal,
metal and plastic. Water-
resistant.
Examples: I/P, heavy metal
rattles, isolating brackets.-40É to 180É
Fahrenheit
(-40É to 82É Celsius)
Open Cell Foam
TapeSoft foam conforms to irregular
surfaces.Wire harness and connector
wrap.
Examples: Seals, gasket,
wiring, heat ducts.-40É to 180É
Fahrenheit
(-40É to 82É Celsius)
Closed Cell Low
Density Foam TapeSoft, conformable. Water-
resistant.Wherever bulk is needed.
Prevents closing flutters and
rattles when applied to door
watershield.
Examples: Door, I/P.-40É to 180É
Fahrenheit
(-40É to 82É Celsius)
NYETGrease 880 Long life. Suspensions.
Examples: Strut busings, sway
bars.-40É to 390É
Fahrenheit
(-40É to 200É
Celsius)
KrytoxTOil Long life. Will not dry out or
harm plastics or rubber.When access is not possible, oil
will migrate to condition. Vinyl,
rubber, plastic, metal.
Examples: Convertible top
bushings, pull cups trim panel
inserts.-30É to 400É
Fahrenheit
(-34É to 205É
Celsius)
KrytoxTGrease Long life. Will not dry out or
harm plastics or rubber.Vinyl, rubber, plastic, metal,
glass.
Examples: Weather-strips,
backlite and windshield
moldings.-30É to 400É
Fahrenheit
(-34É to 205É
Celsius)
DRBODY 23 - 11
BODY (Continued)
Page 2488 of 2627

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING
SYSTEM REQUIREMENTS...............1
DESCRIPTION - HEATER AND AIR
CONDITIONER........................1
OPERATION - HEATER AND AIR
CONDITIONER........................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE.......................3DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST..................6
SPECIFICATIONS - A/C SYSTEM............7
CONTROLS.............................9
DISTRIBUTION..........................26
PLUMBING.............................41
HEATING & AIR
CONDITIONING
DESCRIPTION
DESCRIPTION - ENGINE COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the heating,
ventilation and air conditioning (HVAC) system, the
engine cooling system must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or A/C condenser
will reduce the performance of the A/C and engine
cooling systems.
The engine cooling system includes the radiator,
thermostat, radiator hoses and the engine coolant
pump. Refer to Cooling for more information before
opening or attempting any service to the engine cool-
ing system.
DESCRIPTION - HEATER AND AIR
CONDITIONER
A manually controlled single zone type heating-air
conditioning system or a manually controlled dual
zone type heating-air conditioning system is available
on this model.
All vehicles are equipped with a common heater,
ventilation and air conditioning (HVAC) housing (Fig.
1). The system combines air conditioning, heating,
and ventilating capabilities in a single unit housing
mounted within the passenger compartment under
the instrument panel. The HVAC housing includes:
²Blower motor
²Blower motor resistor block²Heater core
²Evaporator coil
²Blend door and actuator
²Defrost door and actuator
²Mode door and actuator
²Recirculation door and actuator
Based upon the system and mode selected, condi-
tioned air can exit the HVAC housing through one or
a combination of the three main housing outlets:
defrost, panel or floor. The defrost outlet is located on
the top of the housing, the panel outlet is located on
the face of the housing and the floor outlet is located
on the bottom of the housing. Once the conditioned
air exits the unit housing, it is further directed
through molded plastic ducts to the various outlets in
the vehicle interior. These outlets and their locations
are as follows:
²Defroster Outlet- A single large defroster out-
let is located in the center of the instrument panel
top cover, near the base of the windshield.
²Side Window Demister Outlets- There are
two side window demister outlets, one is located at
each outboard end of the instrument panel top cover,
near the belt line at the A-pillars.
²Panel Outlets- There are four panel outlets in
the instrument panel, one located near each outboard
end of the instrument panel facing the rear of the
vehicle and two located near the top of the instru-
ment panel center bezel.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the floor panel
center tunnel near the dash panel.
OPERATION - HEATER AND AIR CONDITIONER
The heating and air conditioning systems pulls
outside (ambient) air through the cowl opening at the
base of the windshield, then into the plenum cham-
DRHEATING & AIR CONDITIONING 24 - 1
Page 2489 of 2627

ber above the heating, ventilation and air condition-
ing (HVAC) housing. On models equipped with air
conditioning, the air passes through the evaporator
coil. Air flow can be directed either through or
around the heater core. This is done by adjusting the
blend door with the temperature control knob on the
A/C-heater control located the instrument panel. The
air flow can then be directed from the panel, floor
and defrost outlets in various combinations using the
mode control knob located on the A/C-heater control.
Air flow velocity can be adjusted with the blower
speed selector located on the A/C-heater control.
NOTE: It is important to keep the air intake opening
clear of debris. Leaf particles and other debris that
is small enough to pass through the cowl opening
screen can accumulate within the HVAC housing.
The closed, warm, damp and dark environment cre-
ated within the housing is ideal for the growth of
certain molds, mildews and other fungi. Any accu-mulation of decaying plant matter provides an addi-
tional food source for fungal spores, which enter
the housing with the fresh intake-air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during heater-A/C
operation if the air intake opening is not kept clear
of debris.
The heater and air conditioning systems are blend-
air type systems. In a blend-air system, a blend door
controls the amount of unconditioned air (or cooled
air from the evaporator on models with air condition-
ing) that is allowed to flow through, or around, the
heater core. A temperature control knob determines
the discharge air temperature by actuating an elec-
tric motor, which operates the blend door. This allows
an almost immediate control of the output air tem-
perature of the system.
On all models, the outside air intake can be shut
off by selecting the Recirculation Mode with the
mode control knob. This will operate a electric actu-
ated recirculation air door that closes off the outside
fresh air intake and recirculates the air that is
already inside the vehicle.
The air conditioning compressor can be engaged in
any mode by pressing the snowflake, A/C on/off but-
ton. It can also be engaged by placing the mode con-
trol in the mix to defrost positions. This will remove
heat and humidity from the air before it is directed
through or around the heater core. The mode control
knob on the A/C-heater control is used to also direct
the conditioned air to the selected system outlets.
The mode control switch uses an electric motor to
control the mode doors.
The defroster outlet receives airflow from the
HVAC housing through the molded plastic defroster
duct, which connects to the HVAC housing defroster
outlet. The airflow from the defroster outlets is
directed by fixed vanes in the defroster outlet grilles
and cannot be adjusted. The defroster outlet grilles
are integral to the instrument panel top cover.
The side window demister outlets receive airflow
from the HVAC housing through the molded plastic
defroster duct and two molded plastic demister ducts.
The airflow from the side window demister outlets is
directed by fixed vanes in the demister outlet grilles
and cannot be adjusted. The side window demister
outlet grilles are integral to the instrument panel.
The demisters direct air from the HVAC housing
through the outlets located on the top corners of the
instrument panel. The demisters operate when the
mode control knob is positioned in the floor-defrost
and defrost-only settings. Some air may be noticeable
from the demister outlets when the mode control is
in the bi-level to floor positions.
Fig. 1 HVAC Housing - Dual Zone Shown, Single
Zone Typical
1 - NUT
2 - PASSENGER BLEND DOOR ACTUATOR
3 - NUT
4 - INLET BAFFLE
5 - RECIRCULATION DOOR ACTUATOR
6 - RECIRCULATION DOOR
7 - DRIVER SIDE BLEND DOOR ACTUATOR
8 - HVAC HOUSING
9 - BOLT
10 - DEFROSTER DOOR ACTUATOR
11 - MODE DOOR ACTUATOR
24 - 2 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)
Page 2490 of 2627

The panel outlets receive airflow from the HVAC
housing through a molded plastic main panel duct,
center panel duct and two end panel ducts. The two
end panel ducts direct airflow to the left and right
instrument panel outlets, while the center panel duct
directs airflow to the two center panel outlets. Each
of these outlets can be individually adjusted to direct
the flow of air.
The floor outlets receive airflow from the HVAC
housing through the floor distribution duct. The front
floor outlets are integral to the molded plastic floor
distribution duct, which is secured to the bottom of
the housing. The floor outlets cannot be adjusted.
The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a fixed
orifice tube in the liquid line near the condenser out-
let tube to meter refrigerant flow to the evaporator
coil. To maintain minimum evaporator temperature
and prevent evaporator freezing, a evaporator tem-
perature sensor is used. The JTEC control module is
programmed to respond to the evaporator tempera-
ture sensor input by cycling the air conditioning com-
pressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to remove
heat and humidity from the air entering the passen-
ger compartment. The evaporator, located in the
HVAC housing, is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins in the evaporator, moisture in the air condenses
to water, dehumidifying the air. Condensation on the
evaporator fins reduces the evaporators ability to
absorb heat. During periods of high heat and humid-
ity, an air conditioning system will be less effective.
With the instrument control set to Recirculation
mode, only air from the passenger compartment
passes through the evaporator. As the passenger com-
partment air dehumidifies, A/C performance levels
rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the air condition-
ing system. When humidity is high, the evaporator
has to perform a double duty. It must lower the air
temperature, and it must lower the temperature ofthe moisture in the air that condenses on the evapo-
rator fins. Condensing the moisture in the air trans-
fers heat energy into the evaporator fins and tubing.
This reduces the amount of heat the evaporator can
absorb from the air. High humidity greatly reduces
the ability of the evaporator to lower the temperature
of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
air conditioning system on humid days. A perfor-
mance test is the best way to determine whether the
system is performing up to standard. This test also
provides valuable clues as to the possible cause of
trouble with the air conditioning system.
PERFORMANCE TEST PROCEDURE
Review Safety Warnings and Cautions before per-
forming this procedure (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION). Air temperature in test
room and on vehicle must be 21É C (70É F) minimum
for this test.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a tachometer and a manifold gauge set
or A/C recycling/charging station.
(2) Set the A/C-heater mode control in the Recircu-
lation Mode position, the temperature control knob in
the full cool position, and the blower motor switch to
the highest speed position.
(3) Start the engine and hold at 1,000 rpm with
the A/C compressor clutch engaged.
(4) The engine should be warmed up to operating
temperature with the doors closed and windows
open.
(5) Insert a thermometer in the driver side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) The compressor clutch may cycle, depending
upon the ambient temperature and humidity.
(7) With the compressor clutch engaged, record the
discharge air temperature and the compressor dis-
charge pressure.
(8) If the discharge air temperature fails to meet
the specifications in the A/C Performance Tempera-
ture chart, refer to the Pressure Diagnosis chart.
DRHEATING & AIR CONDITIONING 24 - 3
HEATING & AIR CONDITIONING (Continued)
Page 2491 of 2627

PERFORMANCE TEMPERATURE AND PRESSURE
Ambient Air
Temperature21É C
(70É F)27É C
(80É F)32É C
(90É F)38É C
(100É F)43É C
(110É F)
Air Temperature at
Center Panel Outlet7É C
(45É F)7É C
(45É F)13É C
(55É F)13É C
(55É F)18É C
(64É F)
Compressor Inlet
Pressure at Service
Port (low Side)138 to 207 kPa
(20 to 30 psi)172 to 241 kPa
(25 to 35 psi)207 to 276
kPa
(30 to 40 psi)241 to 310
kPa
(35 to 45 psi)276 to 345 kPa
(40 to 50 psi)
Compressor
Discharge Pressure at
Service Port (High
Side)1034 to 1724
kPa
(150 to 250
psi)1379 to 2068
kPa
(200 to 300
psi)1724 to 2413
kPa
(250 to 350
psi)1999 to 2689
kPa
(290 to 390
psi)2413 to 2965
kPa
(350 to 430 psi)
(9) Compare the compressor discharge pressure to
the Performance Temperature and Pressure chart. Ifthe compressor discharge pressure is high, see the
Pressure Diagnosis chart.
PRESSURE DIAGNOSIS
Condition Possible Causes Correction
Constant compressor
engagement and warm air
from passenger vents.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
Equal pressures, but the
compressor clutch does not
engage.1. No refrigerant in the
refrigerant system.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
2. Faulty fuse. 2. Check the fuses in the Power Distribution
Center and the junction block. Repair the shorted
circuit or component and replace the fuses, if
required.
3. Faulty A/C compressor
clutch coil.3. See A/C Compressor Clutch Coil in this group.
Test the compressor clutch coil and replace, if
required.
4. Faulty A/C compressor
clutch relay.4. See A/C Compressor Clutch Relay in this
group. Test the compressor clutch relay and relay
circuits. Repair the circuits or replace the relay, if
required.
5. Improperly installed or
faulty Evaporator
Temperature Sensor.5. See Evaporator Temperature Sensor in this
group. Reinstall or replace the sensor as
required.
6. Faulty A/C pressure
transducer.6. See A/C pressure transducer in this group.
Test the switch and replace, if required.
7. Faulty Powertrain Control
Module (PCM).7. (Refer to Appropriate Diagnostic Information).
Test the PCM and replace, if required.
24 - 4 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)
Page 2492 of 2627

Condition Possible Causes Correction
Normal pressures, but A/C
Performance Test air
temperatures at center panel
outlet are too high.1. Excessive refrigerant oil in
system.1. See Refrigerant Oil Level in this group.
Recover the refrigerant from the refrigerant
system and inspect the refrigerant oil content.
Restore the refrigerant oil to the proper level, if
required.
2. Blend door inoperative or
sealing improperly.2. See Blend Door in this group. Inspect the
blend door for proper operation and sealing and
correct, if required.
3. Blend door actuator faulty
or inoperative.3. Perform blend door actuator diagnosis, replace
if faulty.
The low side pressure is
normal or slightly low, and the
high side pressure is too low.1. Low refrigerant system
charge.1. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
2. Refrigerant flow through
the accumulator is restricted.2. See Accumulator in this group. Replace the
restricted accumulator, if required.
3. Refrigerant flow through
the evaporator coil is
restricted.3. See A/C Evaporator in this group. Replace the
restricted evaporator coil, if required.
4. Faulty compressor. 4. See A/C Compressor in this group. Replace
the compressor, if required.
The low side pressure is
normal or slightly high, and
the high side pressure is too
high.1. Condenser air flow
restricted.1. Check the A/C condenser for damaged fins,
foreign objects obstructing air flow through the
condenser fins, and missing or improperly
installed air seals. Refer to Cooling for more
information on air seals. Clean, repair, or replace
components as required.
2. Inoperative cooling fan. 2. Refer to Cooling for more information. Test the
cooling fan and replace, if required.
3. Refrigerant system
overcharged.3. See Refrigerant System Charge in this group.
Recover the refrigerant from the refrigerant
system. Charge the refrigerant system to the
proper level, if required.
4. Air in the refrigerant
system.4. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
5. Engine overheating. 5. Refer to Cooling for more information. Test the
cooling system and repair, if required.
The low side pressure is too
high, and the high side
pressure is too low.1. Accessory drive belt
slipping.1. Refer to Cooling for more information. Inspect
the accessory drive belt condition and tension.
Tighten or replace the accessory drive belt, if
required.
2. Fixed orifice tube not
installed.2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.
3. Faulty compressor. 3. See A/C Compressor in this group. Replace
the compressor, if required.
DRHEATING & AIR CONDITIONING 24 - 5
HEATING & AIR CONDITIONING (Continued)
Page 2498 of 2627

(6) Insert the two pins of the spanner wrench
(Special Tool C-4489 or equivalent) into the holes of
the clutch plate. Hold the clutch plate stationary and
remove the hex nut (Fig. 2).
(7) Remove the clutch plate.
(8) Remove the compressor clutch shims.
(9) Remove the external front housing snap ring
with snap ring pliers (Fig. 3).
(10) Install the lip of the rotor puller (Special Tool
C-6141-1 or equivalent) into the snap ring groove
exposed in the previous step, and install the shaft
protector (Special Tool C-6141-2 or equivalent) (Fig.
4).
(11) Install the puller through-bolts (Special Tool
C-6461 or equivalent) through the puller flange and
into the jaws of the rotor puller and tighten (Fig. 5).Turn the puller center bolt clockwise until the rotor
is free.
CAUTION: DO NOT APPLY FORCE TO THE END OF
THE COMPRESSOR SHAFT.
(12) Remove the screw and retainer from the
clutch coil lead wire harness on the compressor front
housing (Fig. 6).
(13) Remove the snap ring from the compressor
hub and remove the clutch field coil (Fig. 7). Slide
the clutch field coil off of the compressor hub.
INSPECTION
Examine the friction surfaces of the clutch pulley
and the clutch plate for wear. The pulley and clutch
plate should be replaced if there is excessive wear or
scoring.
Fig. 2 Clutch Nut Remove - Typical
1 - CLUTCH PLATE
2 - SPANNER
Fig. 3 External Snap Ring Remove - Typical
1 - PULLEY
2 - SNAP RING PLIERS
Fig. 4 Shaft Protector and Puller - Typical
1 - PULLER JAW
2 - SHAFT PROTECTOR
Fig. 5 Install Puller Plate - Typical
1 - PULLER JAW
2 - PULLER
DRCONTROLS 24 - 11
A/C COMPRESSOR CLUTCH/COIL (Continued)
Page 2501 of 2627

spikes and electromagnetic interference that can be
generated as the electromagnetic field of the relay
coil collapses.
The A/C compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the integrated power module (IPM). The
inputs and outputs of the A/C compressor clutch
relay include:
²The common feed terminal (30) receives a bat-
tery current input from a fuse in the IPM through a
fused B(+) circuit at all times.
²The coil ground terminal (86) receives a ground
input from the PCM/ECM through the A/C compres-
sor clutch relay control circuit only when the PCM/
ECM electronically pulls the control circuit to
ground.
²The coil battery terminal (85) receives a battery
current input from PTC 1 in the IPM through a
fused ignition switch output (run) circuit only when
the ignition switch is in the On position.
²The normally open terminal (87) provides a bat-
tery current output to the compressor clutch coil
through the A/C compressor clutch relay output cir-
cuit only when the A/C compressor clutch relay coil is
energized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the A/C compres-
sor clutch relay coil is de-energized.
Refer to the appropriate wiring information for
diagnosis and testing of the micro-relay and for com-
plete HVAC wiring diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the integrated power
module (IPM) (Fig. 11).
(3) Refer to the fuse and relay layout label on the
IPM cover for compressor clutch relay identification
and location.
(4) Remove the A/C compressor clutch relay from
the IPM.
INSTALLATION
(1) See the fuse and relay layout label affixed to
the underside of the IPM cover for A/C compressor
clutch relay location.
(2) Position the A/C compressor clutch relay in the
proper receptacle in the IPM.
(3) Align the A/C compressor clutch relay termi-
nals with the terminal cavities in the IPM receptacle.
(4) Push down firmly on the A/C compressor clutch
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install the cover onto the IPM.(6) Reconnect the negative battery cable.
A/C HEATER CONTROL
DESCRIPTION
The heater and air conditioning systems use elec-
trical controls. These controls provide the vehicle
operator with a number of setting options to help
control the climate and comfort within the vehicle.
The A/C-heater control for the Single Zone system
(Fig. 12) or Dual Zone system (Fig. 13) is located to
the right of the instrument cluster on the instrument
panel.
The Single Zone control panel contains a rotary-
type temperature control switch, a rotary-type mode
control switch and a rotary-type blower motor speed
switch. The A/C-heater control also has a push but-
ton to activate the optional heated side view mirror
defroster elements and to turn the A/C on.
The Dual Zone control panel contains a pair of slid-
er-type temperature control switches, a rotary-type
mode control switch and a rotary-type blower motor
speed switch. The control also has buttons to activate
the optional heated sideview mirror defroster ele-
ments, turn the A/C on and set the system to Max
A/C.
The A/C-heater control panel cannot be repaired. If
faulty or damaged, the entire unit must be replaced.
Fig. 11 Integrated Power Module (IPM)
1 - BATTERY
2 - INTEGRATED POWER MODULE (IPM)
24 - 14 CONTROLSDR
A/C COMPRESSOR CLUTCH RELAY (Continued)