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HEATING AND AIR CONDITIONING 24 - 1
HEATING AND AIR CONDITIONING
CONTENTS
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CLIMATE CONTROL SYSTEM ..............
COMPRESSOR SERVICE PROCEDURES .....
GENERAL INFORMATION ..................
SYSTEM DIAGNOSTICS ...................
REFRIGERANT SERVICE PROCEDURES ......
TORQUE SPECIFICATIONS ................
GENERAL INFORMATION
INDEX
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Air Conditioning System ....................
Component Description ....................
Cooling System ..........................
Handling Tubing and Fittings ................
Heater System ...........................
Refrigerant .............................
Refrigerant Safety Precautions and Warnings for R134A
......................................
Side Window Demisters ....................
System Airflow ...........................
Both the heater and the heater/air conditioning sys-
tems share many of the same functioning compo-
nents. This Group will deal with both systems to-
gether when component function is common and
separately when they are not. The automatic tem-
perature control (ATC) system diagnostics is dealt
with separately.
For proper operation of the instrument panel con-
trols (Fig. 1), refer to the Owner’s Manual provided
with the vehicle.
All vehicles are equipped with a common heater-
A/C unit housing assembly (Fig. 2). On heater only
systems, the evaporator coil is omitted and replaced
with an air restrictor plate.
HEATER SYSTEM
All models use a Blend-Air type heater. Outside air
enters the heater through the cowl opening and
passes through a plenum chamber to the heater core.
Air intake openings must be kept free of snow, ice and
other obstructions for the heater system to pick up a
sufficient volume of outside air. A temperature control
door in the heater housing directs incoming air
through and/or around the heater core. The amount of
blend (heated and non-heated air) is determined by
the setting of the temperature knob on the instru-
ment panel. Direction of the blended air is controlled
by the mode knob on the instrument panel.
The blower switch and resistor block controls the
speed of the blower motor. This in turn controls the
Fig. 1 Heater, Manual A/C and ATC Controls
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SYSTEM AIRFLOW
Refer to Fig. 3 for the system airflow. The system
pulls outside (ambient) air through the cowl opening
at the base of the windshield. Then it goes into the
plenum chamber above the heater-A/C unit housing.
On air conditioned vehicles, the air passes through
the evaporator. Air flow can be directed either
through or around the heater core. This is done by
adjusting the blend-air door with the TEMP control
on the instrument panel. The air flow can then be di-
rected from the PANEL, BI-LEVEL (panel and floor),
FLOOR, FLOOR/DEFROST or DEFROST outlets.
Air flow velocity can be adjusted with the blower
speed selector switch on the instrument panel.
Fig. 2 Common Blend-Air Heater-A/C System
velocity of the air flow from the FLOOR (heater),
DEFROST or PANEL outlets.
SIDE WINDOW DEMISTERS
The side window demisters direct air from the
heater assembly. The outlets are located on the top
left and right edges of the door panels. The Demis-
ters operate when the control mode selector is on
FLOOR, BI-LEVEL, FLOOR/DEFROST or DE-
FROST mode.
AIR CONDITIONING SYSTEM
The A/C system uses a 10PA17 fixed displacement
compressor. A label identifying the use of R-134a re-
frigerant is located on the compressor.
Fig. 3 Heater-A/C System Airflow (Front View)
CAUTION: DO NOT use an R-12 compressor on an
R-134a system. The systems are not compatible.
On air conditioned vehicles, outside air can be shut
off by opening the recirculating air door. This will re-
circulate the air that is already inside the vehicle.
This is done by rotating the TEMP control knob into
the RECIRC position.
The air conditioning system has an evaporator to
cool and dehumidify the incoming outside air prior to
blending with the heated air. The compressor is in
operation during the FLOOR/DEFROST mode, DE-
FROST mode and when the A/C button is engaged.
The compressor is not in operation at ambient tem-
peratures below approximately -1°C (30°F). To main-
tain minimum evaporator temperature, a fixed
pressure setting switch cycles the compressor clutch.
The blower is operating in the heater or air condi-
tioning systems, except in the OFF mode. In the OFF
mode the blower and the outside air are shut off.
The Automatic Temperature Control (ATC) system
lets the operator change the passenger compartment
comfort conditions. A computer, built into the control
panel, regulates the desired temperature, air flow di-
rection and blower speed. The operator may also se-
lect an AUTO mode feature in which the computer
would select the blower speed and air flow direction.
Refer to the Owner’s Manual for proper operation.
REFRIGERANT
This vehicle uses a new type of refrigerant called
R-134a. It is a non-toxic, non-flammable, clear color-
less liquified gas.
R-134a refrigerant is not compatible with R-12 re-
frigerant in an air conditioning system. Even a small
amount of R-12 in a R-134a system will cause com-
pressor failure, refrigerant oil sludge or poor air con-
ditioning system performance.
CAUTION: Never add R-12 to a system designed to
use R-134a. Damage to the system will result.
The service port to charge the air conditioning sys-
tem is located on the condenser to evaporator tube
near the cowl panel. New service port couplers have
been used to ensure that the system is not acciden-
tally filled with the wrong refrigerant (R-12).
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HEATING AND AIR CONDITIONING 24 - 3
R-134a refrigerant requires a special type of com-
pressor oil (ND8 PAG). When adding oil, make sure
that it is designed to be used in a R-134a system.
CAUTION: DO NOT use R-12 equipment or parts on
the R-134a system. Damage to the system will re-
sult.
CAUTION: R-12 compressor oil can not be mixed
with the R-134a compressor oil. They ARE NOT
compatible.
COOLING SYSTEM
REQUIREMENTS
To maintain the performance level of the
heating/air conditioning 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 condenser can
reduce the performance of the A/C and/or the engine
cooling system.
Due to the different characteristics of R-134a it
requires all new service procedures. Refer to Refriger-
ant Service Procedures in this section before making
any repairs to the air conditioning system.
Chrysler Corporation recommends that an (R-
134a) refrigerant recycling device that meets
SAE standard J2210 be used.
Contact an automo-
tive service equipment supplier for refrigerant recy-
cling equipment that is available in your area. Refer
to the operating instructions provided with the recy-
cling equipment for proper operation.
PRECAUTIONS
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWALLOWED
OR INHALED. IF SWALLOWED, DRINK TWO
GLASSES OF WATER AND INDUCE VOMITING. IF
INHALED, MOVE TO FRESH AIR AREA. SEEK MEDI-
CAL ATTENTION IMMEDIATELY.
REFRIGERANT SAFETY PRECAUTIONS AND
WARNINGS FOR R134a
WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND/OR THROAT. WEAR
EYE PROTECTION WHEN SERVICING THE AIR CON-
DITIONING REFRIGERANT SYSTEM. SERIOUS EYE
INJURY CAN RESULT FROM EYE CONTACT WITH
REFRIGERANT. IF EYE CONTACT IS MADE, SEEK
MEDICAL ATTENTION IMMEDIATELY.
WARNING: WASH SKIN AND CLOTHING THOR-
OUGHLY AFTER COMING IN CONTACT WITH ETH-
YLENE GLYCOL.
WARNING: KEEP OUT OF REACH OF CHILDREN
AND PETS.
WARNING: DO NOT EXPOSE REFRIGERANT TO
OPEN FLAME. POISONOUS GAS IS CREATED
WHEN REFRIGERANT IS BURNED. AN ELECTRONIC
TYPE LEAK DETECTOR IS RECOMMENDED.
WARNING: DO NOT OPEN A COOLING SYSTEM
WHEN THE ENGINE IS AT RUNNING TEMPERA-
TURE. PERSONAL INJURY CAN RESULT.
WARNING: IF ACCIDENTAL SYSTEM DISCHARGE
OCCURS, VENTILATE THE WORK AREA BEFORE
RESUMING SERVICE. LARGE AMOUNTS OF RE-
FRIGERANT RELEASED IN A CLOSED WORK AREA
WILL DISPLACE THE OXYGEN AND CAUSE SUFFO-
CATION.
WARNING: DO NOT STORE IN OPEN OR UN-
MARKED CONTAINERS.
The engine cooling system is designed to develop
internal pressure of 97 to 124 kPa (14 to 18 psi).
Allow the vehicle 15 minutes to cool down (or until a
safe temperature and pressure are attained) before
opening the cooling system. Refer to Group 7, Cooling
System.
WARNING: THE EVAPORATION RATE OF (R-134A)
REFRIGERANT AT AVERAGE TEMPERATURE AND
ALTITUDE IS EXTREMELY HIGH. AS A RESULT, ANY-
THING THAT COMES IN CONTACT WITH THE RE-
FRIGERANT WILL FREEZE. ALWAYS PROTECT
SKIN OR DELICATE OBJECTS FROM DIRECT CON-
TACT WITH REFRIGERANT.
HANDLING TUBING AND FITTINGS
The air conditioning hoses used on this vehicle are
made from reinforced rubber with a nylon liner on
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with equipment being used.
 24 - 4 HEATING AND AIR CONDITIONING
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the inner walls. The ends of the A/C hoses are made
from light-weight aluminum and use new braze-less
fittings.
The A/C hoses use special connectors called QUICK
CONNECTS. Never attempt to disconnect a quick
connect without discharging the air conditioning sys-
tem. All quick connects use two O-rings to seal the
connection. The O-rings are made from a special type
of rubber that is not affected by R-134a refrigerant.
If O-ring replacement is required be sure to use the
correct type of O-ring. Failure to use the correct type
of O-ring will cause the connection to leak within a
short period of time.
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the ca-
pacity 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.
The following precautions must be observed:
ready. The system should not be left open any longer
than necessary. Cap or plug all lines and fittings as
soon as they are opened to prevent the entrance of
dirt and moisture. All lines and components in parts
stock should be capped or sealed until they are ready
to be used.
(7) All tools, including the refrigerant recycling
equipment, the manifold gauge set and test hoses
should be kept clean and dry. All tools and equip-
ment must be designed for the R-134a refrigerant.
COMPONENT DESCRIPTION
COMPRESSOR
The A/C system uses a Model 10PA17 fixed dis-
placement compressor (Fig. 4 or 5). This compressor
is a 10 piston double acting type. The compressor is
mounted on the front right side of the 4.0L engine
and on the front left side of the 5.2L engine. The
compressor is driven by a serpentine drive belt. The
system is lubricated with polyalkylene glycol syn-
thetic wax-free refrigerant oil (ND8 PAG).
The clutch used on the compressor consists of three
basic components: the pulley, front plate and the
field coil. The pulley and field coil are attached to
the front head of the compressor with tapered snap
rings. The hub is attached to the compressor shaft
and is retained with a compressor shaft bolt. Special
service tools are required to remove and install the
clutch plate on the compressor shaft.
CAUTION: DO NOT use R-12 equipment or parts on
the R-134a system. Damage to the system will re-
sult.
(1) The refrigerant system must be completely dis-
charged into a refrigerant recovery/recycling device
before opening any fitting or connection. Open fit-
tings with caution even after the system has been
discharged. If any pressure is noticed as a fitting is
loosened, allow trapped pressure to bleed off very
slowly into an approved recycling device.
(2) DO NOT discharge refrigerant into the atmo-
sphere. Use an R-134a refrigerant recycling device
that meets SAE Standard J2210.
(3) 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 re-
frigerant. The flexible hose lines should be routed so
they are at least 80 mm (3 in) from the engine ex-
haust manifold. Inspect all flexible hose lines to
make sure they are in good condition and properly
routed.
(4) The use of correct tools when making connec-
tions is very important. Improper tools or improper
use of tools can damage the fittings.
(5) The A/C system will remain chemical stable as
long as pure-moisture-free R-134a refrigerant oil is
used. Abnormal amounts of dirt, moisture or air can
upset the chemical stability. This condition could
cause operational troubles or even serious damage if
present in more than very small quantities.
(6) When it is necessary to open the refrigeration
system, have everything needed to service the system
EVAPORATOR CORE
The evaporator core is located in the heater-A/C
unit (Fig. 4 or 5). It is the plate fin type with a
multi-pass refrigerant flow path. A mixture of refrig-
erant and oil enters the bottom of the core. It then
flows through the evaporator inlet tube and is routed
so that it flows in a W pattern through the evapora-
tor and out the outlet tube.
CONDENSER
The air conditioning condenser is an aluminum
heat exchanger located in front of the radiator (Fig. 4
or 5). It cools compressed refrigerant gas. This is
done by allowing air to pass over fins and tubes to
extract heat and condense gas to liquid refrigerant as
it is cooled.
The condenser inlet and outlet connections require
a special service tool to disconnect the refrigerant
lines from the condenser. To disconnect and recon-
nect the spring lock coupling, refer to SPRING
LOCK COUPLING in this section.
SPRING LOCK COUPLING
The spring lock coupling (Fig. 4 or 5) is a refriger-
ant line coupling held together by a garter spring in-
side a circular cage. When the coupling is connected
together, the flared end of the female fitting slips be-
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HEATING AND AIR CONDITIONING 24 - 5
coupling. Use only the O-rings listed in the parts
book for the spring lock coupling.
A plastic indicator ring is used on spring lock cou-
plings to indicate, during vehicle assembly, that the
coupling is connected. Once the coupling is con-
nected, the indicator ring is no longer necessary but
will remain captive by the coupling near the cage
opening.
The indicator ring may also be used during service
operations to indicate connection of the coupling. Af-
ter the coupling has been cleaned, new O-rings in-
stalled and lubricated with clean refrigerant oil,
insert the tabs of the indicator ring into the cage
opening. Connect the coupling together by pushing
with a slight twisting motion. When the coupling is
connected, the indicator ring will snap out of the
cage opening. It will also remain captured on the
coupling by the refrigerant line.
Fig. 4 Heater-A/C Components (4.0L Engine)
COUPLING DISCONNECT
(1) Discharge the refrigerant from the system us-
ing a recovery/recycling device.
(2) Fit the appropriate Spring Lock Coupling Tool
from A/C Tool Kit 6125 (Fig. 6).
Fig. 5 Heater-A/C Components (5.2L Engine)
Fig. 6 Spring Lock Coupling Disconnect
hind the garter spring inside the cage of the male fit-
ting. The garter spring and cage prevent the flared
end of the female fitting from pulling out of the cage.
Two O-rings are used to seal between the two
halves of the coupling. These O-rings are made of
special material that are compatible with R-134a re-
frigerant and must be replaced with an O-ring made
of the same material. The O-rings normally used in
refrigerant system connections are not the same ma-
terial and should not be used with the spring lock
(3) Close the tool and push into the open side of
the cage to expand garter spring and release female
fitting.
The garter spring may not release if the tool is
cocked while pushing it into the cage opening.
(4) After garter spring is expanded, pull fittings
apart within the tool.
(5) Remove the tool from the disconnected cou-
pling.
(6) Separate the two ends of the coupling.
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