PRESSURE GAUGES
High quality dial type air pressure gauges are rec-
ommended. After checking pressure with the gauge,
replace valve caps and tighten finger tight.
TIRE INFLATION PRESSURES
Under inflation (Fig. 1) causes rapid shoulder wear
and tire flexing and can result in tire failure.
Over inflation (Fig. 2) cause rapid center wear and
loss of the tire's ability to cushion shocks.
Improper inflation can cause:
² Uneven wear patterns
² Reduced tread life
² Reduced fuel economy
² Unsatisfactory ride
² The vehicle to drift.
Proper tire pressure can be found on the placard
attached to the vehicle, See Owner's Manual. This pressure has been selected to provide safe ve-
hicle operation, proper vehicle stability, and a
smooth ride. Tire pressure should be checked cold
once per month and more frequently when the weather temperature varies widely. Tire pressure will
decreases when the outdoor temperature drops.
Inflation pressures specified on the placards are
always cold inflation pressure. Cold inflation pres-
sure is obtained after the vehicle has not been
operated for at least 3 hours or driven less than
one mile after being inoperative for 3 hours. Tire
inflation pressures may increase from 2 to 6 pounds
per square inch (psi) during operation. Do NOT reduce
this normal pressure build-up. Cold inflation pressures must not exceed 240 kPa (35
psi) for P-Series standard load tires.
TIRE PRESSURES FOR HIGH-SPEED OPERA- TION
Chrysler Corporation advocates driving at safe
speeds within posted speed limits. Where speed limits
or conditions are such that the vehicle can be driven at
high speeds, correct tire inflation pressure is very
important. For speeds up to and including 120 km/h
(75 mph), tires must be inflated to the pressure shown
on the tire placard. For speeds in excess of 120 km/h
(75 mph), tires must be inflated to the maximum
pressure specified on the tire sidewall. Vehicles loaded to the maximum capacity should not
be driven at continuous speeds above 120 km/h (75
mph).
WARNING: OVERINFLATED OR UNDER INFLATED
TIRES CAN AFFECT VEHICLE HANDLING. SUDDEN
TIRE FAILURE CAN RESULT, CAUSING LOSS OF
VEHICLE CONTROL.
For police or emergency vehicles that must be driven
at continuous speeds over 144 km/h (90 mph), special
high-speed tires must be used. Consult tire manufac-
turer for tire and inflation pressure recommendations.
REPLACEMENT TIRES
The original equipment tires on the vehicle have
been engineered to provide a proper balance of many
characteristics such as:
² ride
² noise
² handling
² durability
² tread life
² traction
² rolling resistance
² speed capability
Failure to use equipment replacement tires may
adversely affect the safety and handling of the vehicle. The use of oversize tires not listed in the specification
charts may cause interference with vehicle com-
Fig. 1 Under inflation Wear
Fig. 2 Over inflation Wear
22 - 2 WHEELSÐTIRES Ä
SAFETY PRECAUTIONS AND WARNINGS
WARNING: WEAR EYE PROTECTION WHEN SER-
VICING THE AIR CONDITIONING REFRIGERANT
SYSTEM. SERIOUS EYE INJURY CAN RESULT
FROM EYE CONTACT WITH REFRIGERANT. IF EYE
CONTACT IS MADE, SEEK MEDICAL ATTENTION
IMMEDIATELY. DO NOT EXPOSE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN RE-
FRIGERANT IS BURNED. AN ELECTRONIC TYPE
LEAK DETECTOR IS RECOMMENDED. LARGE AMOUNTS OF REFRIGERANT RELEASED
IN A CLOSED WORK AREA WILL DISPLACE THE
OXYGEN AND CAUSE SUFFOCATION. THE EVAPORATION RATE OF (R-12) 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 SKIN OR
DELICATE OBJECTS FROM DIRECT CONTACT
WITH REFRIGERANT.
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with equipment being used.
COOLING SYSTEM PRECAUTIONS
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT STORE IN OPEN OR UNMARKED CON-
TAINERS. WASH SKIN AND CLOTHING THOROUGHLY AF-
TER COMING IN CONTACT WITH ETHYLENE GLY-
COL. KEEP OUT OF REACH OF CHILDREN AND PETS.
DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE. PER-
SONAL INJURY CAN RESULT.
The engine cooling system is designed to develop
internal pressure of 97 to 123 kPa (14 to 18 psi). Al-
low the vehicle 15 minutes (or until a safe tempera-
ture and pressure are attained) before opening the
cooling system. Refer to Group 7, Cooling System.
HANDLING TUBING AND FITTINGS
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:
The system must be completely empty before open-
ing any fitting or connection in the refrigeration sys-
tem. Open fittings with caution even after the
system has been emptied. If any pressure is noticed
as a fitting is loosened, allow trapped pressure to
bleed off very slowly. 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 3 inches (80 mm) from the exhaust
manifold. Inspect all flexible hose lines to make sure
they are in good condition and properly routed. Unified plumbing connections with aluminum gas-
kets cannot be serviced with O-rings. These gaskets
are not reusable and do not require lubrication be-
fore installing. The use of correct wrenches when making connec-
tions is very important. Improper wrenches or im-
proper use of wrenches can damage the fittings. The A/C system will remain chemical stabile as
long as pure-moisture-free R-12 and 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. When it is necessary to open the refrigeration sys-
tem, have everything needed to service the system
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 or
dirt and moisture. All lines and components in parts
stock should be capped or sealed until they are ready
to be used. All tools, including the refrigerant dispensing man-
ifold, the manifold gauge set, and test hoses should
be kept clean and dry.
Fig. 6 Heater only or HeaterÐA/C Controls
Ä HEATING AND AIR CONDITIONING 24 - 3
NONÐCOMPUTER AIDED DIAGNOSTIC TESTS
Determine whether the operator complaint is due
to a system failure or improper operation of the ATC
system. The system will to go into a maximum heat
or cooling mode if the operator changes the tempera-
ture setting four or more degrees. Check the following:
² Coolant level
² Refrigerant charge
² Drive belt tension
² Radiator air flow
² Radiator fan operation
² Air suction of In-car Temperature Sensor/Aspirator
To check air suction of the Aspirator, place a small
piece of tissue paper over the Aspirator opening on
the instrument panel. This opening is located to the
right of the steering column. The tissue paper should
cling to the opening if system is functioning properly. Bring the engine to normal operating temperature
and proceed with Computer Aided Diagnostic Proce-
dures. Always test the entire system after each re-
pair has been performed.
COMPUTER AIDED DIAGNOSTIC TESTS
The ATC control has a computer capable of trou-
bleshooting the entire ATC system in approximately
60 seconds. The engine must be running and at nor-
mal operating temperature during the test to provide
hot coolant for the heater. During the ATC Diagnostic Test, the computer will
calibrate the Mode and Blend Door actuators.
CAUTION: Do not remove the actuators from the
heater-A/C unit assembly with power applied. Re-
moval should only be done with the Ignition OFF.
The actuators have no mechanical stops to limit the
travel. If the actuator rotates and is not connected
to the unit assembly, it will become un-calibrated.
The Diagnostic Test is capable of checking all elec-
trical signals between the ATC Control Module, ac-
tuators, sensors and blower control. The Diagnostic Test will display two types of Diag-
nostic trouble Codes (Fig. 21). The Diagnostic Trou-
ble Codes numbered 01 through 22, have been
detected during the Diagnostic Test. Diagnostic Trou-
ble Codes numbered 23 through 28, have been de-
tected during normal ATC operation. Diagnostic
Trouble Codes 23 through 28 would then be stored in
the ATC control computer and are only being re-
trieved during the Diagnostic Test.
For electrical pin numbers, refer to the wiring Pin
out charts on the following pages in this section. (1) Start vehicle and allow engine to warm up.
(2) For two seconds, depress the DEFROST,
FLOOR and MODE buttons at the same time. The
ATC control should begin to flash on and off. (3) During the Diagnostic Test perform the follow-
ing symptom tests: (a) Do all display symbols and indicators illumi-
nate ?
Fig. 19 Sun Sensor
Fig. 20 Sun Sensor Removal
Fig. 21 Automatic Temperature Control Diagnostic Trouble Codes
24 - 72 HEATING AND AIR CONDITIONING Ä