1993 CHEVROLET PLYMOUTH ACCLAIM low oil pressure

ponents. Under extremes of suspension and steering
travel tire damage may occur.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE SPEED RATING CAN
CAUSE SUDDEN TIRE FAILURE.
ROTATION
DIRECTIONAL TREAD PATTERN TIRES
Some vehicles are fitted with special high-perfor-
mance tires having a directional tread pattern de-
signed to improve traction on wet pavement. To obtain the full benefits of this design, the tires
must be installed so that they rotate in the correct
direction. This is indicated by arrows on the tire
sidewalls. When wheels and tires are being installed, extra
care is needed to ensure that this direction of rota-
tion is maintained. Refer to Owner's Manual for rotation schedule.
NONDIRECTIONAL TIRES
Tires on the front and rear axles of vehicles oper-
ate at different loads and perform different steering,
driving, and braking functions. For these reasons,
they wear at unequal rates, and tend to develop ir-
regular wear patterns. These effects can be reduced
by timely rotation of tires. Rotation will increase
tread life, help to maintain mud, snow, and wet trac-
tion levels, and contribute to a smooth, quiet ride. The suggested rotation method is the forward-cross
tire rotation method. This method takes advantage of
current tire industry practice which now allows cross
rotation of radial-ply tires. Refer to the owner's man-
ual (usually found in the glove box) for additional in-
formation. Other rotation methods may be used, but
may not have all the benefits of the recommended
method. Always check air pressure and wheel nut tightness
after rotation. Do NOT use oil or grease on studs
or nuts. Refer to Owner's Manual for rotation schedule.
TREAD WEAR INDICATORS
Tread wear indicators (Fig. 3) are molded into the
bottom of the tread grooves. When tread is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band. Tire replacement is necessary when indicators ap-
pear in two or more grooves, or if localized balding
occurs.
REPAIRING LEAKS
For proper repairing, a radial tire must be removed
from the wheel. Repairs should only be made if the
defect or puncture is in the tread area otherwise the
tire should be replaced. Deflate tire completely before dismounting tire
from the wheel. Use lubrication such as a mild soap
solution when dismounting or mounting tire. Use
tools free of burrs or sharp edges which could dam-
age the tire or wheel rim. Before mounting tire on wheel, make sure all rust
scale is removed from the rim and repaint if neces-
sary. Install wheels on vehicle, progressively tightening
wheel nuts to 129 N Im (95 ft. lbs.) torque (See
Wheels).
TIRE NOISE OR VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, wheel irregularities,
or imbalance. To determine if the tires are causing the noise or
vibration, drive the vehicle over a smooth portion of
highway at different speeds and note the effect of ac-
celeration and deceleration on noise level. Differen-
tial and exhaust noise will change in intensity as
speed varies, while tire noise will usually remain
constant.
TIRE WEAR PATTERNS
Under inflation results in faster wear on shoulders
of tire. Over inflation causes faster wear at center of tread.
Excessive camber causes the tire to run at an angle
to the road. One side of tread is worn more than the
other. Excessive toe-in or toe-out causes wear on the
tread edges of the tire, from dragging of tire. There
is a feathered effect across the tread (Fig. 4).
Fig. 3 Tread Wear Indicators
Ä WHEELSÐTIRES 22 - 3

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

REFRIGERANT SERVICE PROCEDURES INDEX
page page
Adding Partial Refrigerant Charge ............ 10
Charging Refrigerant SystemÐEmpty System . . . 11
Discharging Refrigerant System .............. 11
Evacuating Refrigerant System .............. 11
Manifold Gauge Set Connections ............. 9 Oil Level
............................... 12
R-12 Refrigerant Equipment ................. 8
Refrigerant Recycling ...................... 9
Sight Glass Refrigerant Level Inspection ........ 8
Testing for Refrigerant Leaks ............... 10
SIGHT GLASS REFRIGERANT LEVEL INSPECTION
The filter-drier is equipped with a sight glass (Fig.
1) that is used as a refrigerant level indicator only.
This sight glass is not to be used for A/C perfor-
mance testing. To check the refrigerant level re-
move the vehicle jack. Then clean the sight glass,
start and warm up engine, and hold rpm slightly
above idle (1100 rpm). Place the air conditioning con-
trol on A/C, RECIRC and high blower. The work
area should be at least 21ÉC (70ÉF). If a Fixed Dis-
placement type compressor does not engage, the re-
frigerant level is probably too low for the Low
Pressure Cut-Off switch to detect. Or, with a Vari-
able Displacement compressor, for the Differential
Pressure Cut-off to detect. If compressor clutch does
not engage, test the refrigerant system for leaks. If
compressor clutch engages, allow approximately one
minute for refrigerant to stabilize. View refrigerant
through sight glass. The suction line should be cold
to the touch and the sight glass should be clear.
If foam or bubbles are visible in sight glass, the re- frigerant level is probably low. Occasional foam or
bubbles are normal when the work area temperature
is above 43ÉC (110ÉF) or below 21ÉC (70ÉF). If suction
line is cold and occasional bubbles are visible in the
sight glass, block the condenser air flow. This will in-
crease the compressor discharge pressure. Do not al-
low engine to over heat. Bubbles should dissipate.
If not, the refrigerant level is low.
CAUTION: Do not allow engine to over heat while
blocking the condenser air flow.
WARNING: R-12 REFRIGERANT IS DETRIMENTAL
TO THE ENVIRONMENT WHEN RELEASED TO THE
ATMOSPHERE. DO NOT ADD R-12 REFRIGERANT
TO A SYSTEM THAT HAS A KNOWN LEAK.
The refrigerant system will not be low on (R-12)
unless there is a leak. Find and repair the leak be-
fore charging.
R-12 REFRIGERANT EQUIPMENT
WARNING: EYE PROTECTION MUST BE USED
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE PROCEEDING WITH THIS OPERATION.
PERSONNEL INJURY CAN RESULT.
When servicing an air conditioning system, an A/C
charging station is recommended (Fig. 2). An (R-12)
refrigerant recovery/recycling device (Fig. 3) should
also be used. This device should meet SAE standards.
Contact an automotive service equipment supplier
for refrigerant recycling/recovering equipment. Refer
to the operating instructions provided with the
equipment for proper operation. A manifold gauge set (Fig. 4) must also be used in
conjunction with the charging and/or recovery/recy-
cling device. The service hoses on the gauge set be-
ing used should have manual (turn wheel) or
automatic back flow valves at the service port con-
nector ends. This will prevent refrigerant from being
release into the atmosphere.
Fig. 1 Filter Drier and Sight Glass
24 - 8 HEATING AND AIR CONDITIONING Ä

backed off, immediately point the end of hose toward
floor, as possibly trapped refrigerant in the hose will
be released.(e) Install service port cap.
DISCHARGE (HIGH PRESSURE) GAUGE CONNECTION (1) Remove the service port cap from the 1/4 in.
service port. (2) Check all valves on the equipment being used to
verify they are closed. (3) Inspect the hose gasket in the service port con-
nector at the end of the (RED) hose. If the gasket is
flawed, replace it. (4) Use a suitable (3/8 in. male to 1/4 in. female)
adapter (Fig. 5), threaded securely into the end of the
(RED) hose connector.
(5) Thread the 1/4 in. hose adapter connector onto
the service port. Quickly secure adapter connector to
service port to avoid loosing refrigerant. To disconnect the discharge gauge (RED) hose:(a) Wrap the end of hose with a shop towel.
(b) Loosen the hose connector.
(c) Push and hold the end of hose toward the
service port to keep the gasket in contact with service
port. (d) Quickly rotate the connector counterclockwise.
When the hose connector is completely backed off,
immediately point the end of hose toward floor, as
possibly trapped refrigerant in the hose will be
released. (e) Install service port cap.
EVACUATION/RECOVERY/RECYCLING/CHARGING LINE CON-
NECTION
The center manifold (YELLOW) or (WHITE) hose is
used to recycle, recover, evacuate, and charge the
refrigerant system. When the discharge or suction
valves on the manifold gauge set are opened, the
refrigerant in the system will escape through this hose. This hose should be attached to a R-12
Recovery/Recycling device. Refer to the
Recovery/Recycling devices operators manual
for procedures. For disconnection of this hose, refer to Disconnect-
ing the Discharge Gauge (RED) hose in the preced-
ing paragraphs.
TESTING FOR REFRIGERANT LEAKS
If the A/C system is not cooling properly, deter-
mine if the refrigerant system is fully charged with
R-12. Follow the procedures in the Performance Test
Procedures section of this Group. If the refrigerant
system is empty or low in refrigerant charge, a leak
at any line fitting or component seal is likely. To de-
tect a leak in the refrigerant system, perform one of
the following procedures as indicated by the symp-
toms.
EMPTY REFRIGERANT SYSTEM LEAK TEST
CAUTION: Review Safety Precautions and Warnings
in General Information section of this Group.
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible. (2) Prepare a 10 oz. refrigerant (R-12) charge to be
injected into the system. Refer to Charging Refriger-
ant System for instructions. (3) Connect and dispense 10 ozs. of refrigerant into
the evacuated refrigerant system. (4) Proceed to step two of Low Refrigerant Level
Leak Test.
LOW REFRIGERANT LEVEL LEAK TEST
Caution: Review Safety Precautions and Warnings
in the General Information section of this group.
(1) Using the refrigerant level sight glass, deter-
mine if there is any (R-12) refrigerant in the system. (2) Position the vehicle in a wind free work area.
This will aid in detecting small leaks. (3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes. (4) With the engine not running, use an Electronic
Leak Detector (or equivalent) and search for leaks.
Fittings, lines, or components that appear to be oily
usually will indicate a refrigerant leak. To inspect
the evaporator core for leaks, it is possible to insert
the leak detector probe into the recirculating air door
opening (Fig. 6).
ADDING PARTIAL REFRIGERANT CHARGE
After all leaks have been corrected and it was not
necessary to empty the refrigerant system, a partial
refrigerant charge can be added.
CAUTION:Review all Safety Precautions and Warn-
ings before attempting to add refrigerant to the sys-
tem. Do not add refrigerant to a system that is
known to have a leak.
Fig. 5 Discharge Hose Adapter
24 - 10 HEATING AND AIR CONDITIONING Ä

(1) Attach manifold gauge set.
(2) Open the windows of the passenger compart-
ment and set the air conditioning controls to A/C,
RECIRC, and Low blower speed. (3) Start the engine and allow it to warm up to
normal running temperature. (4) If the air conditioning compressor does not en-
gage, disconnect the low pressure cut-off switch.
Place a jumper wire across the terminals in the con-
nector boot. If the compressor still does not engage, a
problem exists in the compressor clutch feed circuit. (6) Hold the engine speed at 1400 rpm.
(7) Following the instructions provided with the
charging equipment being used. Charge through the
suction side of the system. Use enough refrigerant to
clear the sight glass in the filter drier. (8) At the point when the sight glass clears, note
the weight of the refrigerant supply drum or the
level in the charging cylinder. Then add an addi-
tional 340 g (12 oz) of refrigerant to the system. Re- move the jumper wire from the low pressure cut-off
switch connector and connect the cut-off switch.
(9) Test the over all performance of the air condi-
tioner as described in A/C Overall Performance Test
in this Group. Close all valves on the charging equip-
ment and disconnect the hoses from the service ports
as described in the Manifold Gauge Set Connections
section of this Group. Install the service port caps.
DISCHARGING REFRIGERANT SYSTEM
(R-12) refrigerant is a chlorofluorocarbon (CFC)
that can contribute to the depletion of the ozone
layer in the upper atmosphere. To help protect the
ozone layer, an R-12 refrigerant recycling device
must be used. Use this device when it is necessary to
empty the refrigerant system. Contact an automotive
service equipment supplier for refrigerant recycling
equipment. Refer to the operating instructions pro-
vided with the recycling equipment for proper opera-
tion.
EVACUATING REFRIGERANT SYSTEM
If the A/C system has been open to the atmosphere,
it must be evacuated before the system can be
charged. Moisture and air mixed with the refrigerant
will raise the compressor head pressure above accept-
able operating levels. This will reduce the perfor-
mance of the air conditioner and damage the
compressor. Moisture will boil at near room temper-
ature when exposed to vacuum. To evacuate the re-
frigerant system: (1) Connect a suitable charging station, refrigerant
recovery machine, and a manifold gauge set with
vacuum pump. (2) Open the suction and discharge valves and
start the vacuum pump. When the suction gauge
reads -88 kPa (-26 in. Hg) vacuum or greater, close
all valves and turn off vacuum pump. If the system
fails to reach specified vacuum, the refrigerant sys-
tem likely has a leak that must be corrected. If the
refrigerant system maintains specified vacuum for at
least 30 minutes, start the vacuum pump. Then open
the suction and discharge valves, and allow the sys-
tem to evacuate an additional 10 minutes. (3) Close all valves. Turn off and disconnect the
vacuum pump. The refrigerant system is prepared to be charged
with refrigerant.
CHARGING REFRIGERANT SYSTEMÐEMPTY
SYSTEM
CAUTION: Do not over charge refrigerant system,
as excessive compressor head pressure can cause
noise and system failure.
Fig. 6 Testing for A/C LeaksÐTypical Front/Rear A/C System
Ä HEATING AND AIR CONDITIONING 24 - 11

WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS BEFORE CHARGING THE REFRIGER-
ANT SYSTEM.
After the system has been tested for leaks and
evacuated, a refrigerant charge can be injected into
the system. (1) Connect manifold gauge set.
(2) Measure refrigerant (refer to capacities) and
heat to 52ÉC (125ÉF) with the charging station. Refer
to the instructions provided with the equipment be-
ing used.
REFRIGERANT CAPACITIES:
² Without Rear A/C = 907 g (32 oz.)
² With Rear A/C = 1219 g (43 oz.)
(3) Open the suction and discharge valves. Open
the charge valve to allow the heated refrigerant to
flow into the system. When the transfer of refriger-
ant has stopped, close the suction and discharge
valve. (4) If all of the refrigerant charge did not transfer
from the dispensing device, start engine and hold at
idle (1400 rpm). Set the A/C control to A/C, low
blower speed, and open windows. If the A/C compres-
sor does not engage, test the compressor clutch con-
trol circuit and correct any failure. Refer to Group
8W, Wiring Diagrams. (5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system perfor-
mance. Refer to Heater and A/C Performance Tests
in this Group. (7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
OIL LEVEL
It is important to have the correct amount of oil in
the A/C system to ensure proper lubrication of the
compressor. Too little oil will result in damage to the
compressor. Too much oil will reduce the cooling ca-
pacity of the system. The oil used in the compressor is a 500 SUS viscos-
ity, wax-free refrigerant oil. Only refrigerant oil of
the same type should be used to service the system.
Do not use any other oil. The oil container should be
kept tightly capped until it is ready for use, and then
tightly capped after use to prevent contamination
from dirt and moisture. Refrigerant oil will quickly
absorb any moisture it comes in contact with. It will not be necessary to check oil level in the
compressor or to add oil unless there has been an oil
loss. This may be due to a ruptured line, shaft seal leakage, leakage from the evaporator, condenser
leak, filter drier or loss of refrigerant due to a colli-
sion. Oil loss at a the leak point will be evident by
the presence of a wet, shiny surface around the leak.
REFRIGERANT OIL LEVEL CHECK
When an A/C system is assembled at the factory,
all components (except the compressor) are refriger-
ant oil free. After the system has been charged with
R-12 and operated, the oil in the compressor is dis-
persed through the lines and components. The evap-
orator, condenser, and filter-drier will retain a
significant amount of oil. (Refer to the Refrigerant
Oil Capacities chart). When a component is replaced,
the specified amount of refrigerant oil must be
added. When the compressor is replaced, the amount
of oil that is retained in the rest of the system must
be drained from the replacement compressor. When a
refrigerant line or component has ruptured and it
has released an unknown amount of oil. The A/C
compressor should be removed and drained through
the suction port. The filter-drier must be replaced
along with the ruptured part. Then the oil capacity
of the system (minus the amount of oil still in the re-
maining components) can be poured into the suction
port of the compressor. Example: The evaporator retains 60 ml (2 oz). The
condenser retains 30 ml (1 oz) of oil, and system ca-
pacity may be 214 ml (7.25 oz) of oil. 214 ml minus 90 ml = 124 ml (4.25 oz).
VERIFY REFRIGERANT OIL LEVEL
(1) Using a refrigerant recovery machine, remove
refrigerant from the A/C system. (2) Remove refrigerant lines from A/C compressor.
(3) Remove compressor from vehicle.
(4) From suction port on top of compressor, drain
refrigerant oil from compressor. (5) Add system oil capacity minus the capacity of
components that have not been replaced. Refer to the
Refrigerant Oil Capacity chart. Add oil through suc-
tion port on compressor. (6) Install compressor, connect refrigerant lines,
evacuate, and charge refrigerant system.
REFRIGERANT OIL CAPACITIES
24 - 12 HEATING AND AIR CONDITIONING Ä

VARIABLE DISPLACEMENT COMPRESSORÐMODEL 6C17 INDEX
page page
Clutch Coil Tests ......................... 17
Compressor ............................. 17
Compressor Clutch Inoperative .............. 13
Compressor Clutch/Coil Assembly ............ 19
Compressor Diagnosis ..................... 13
Compressor Front Shaft Seal ............... 20 Compressor High Pressure Cut-Out Switch
..... 21
Compressor High Pressure Relief Valve (HPR) . . 22
Compressor Identification ................... 13
Compressor Main or Sub Control Valves ....... 22
Compressor Noise ........................ 13
General Information ....................... 13
GENERAL INFORMATION
The Variable Displacement Compressor (VDC) pro-
vides maximum A/C performance under most condi-
tions. It is designed to operate continuously without
any cycling of the compressor clutch. The compressor
has a variable angle wobble plate with six axially
oriented cylinders. During vehicle A/C system operation, the compres-
sor will change its displacement to match the vehi-
cles A/C cooling demands. When the A/C system
needs more cooling capacity, the compressor will in-
crease its pumping capacity. This is done by increas-
ing the wobble plate angle to increase the piston
stroke. When the A/C system cooling demand is low,
the compressor will decrease its pumping capacity by
reducing the piston pumping stroke. The low cooling
capacity will prevent evaporator from freezing.
COMPRESSOR IDENTIFICATION
The Variable Displacement Compressor can be
identified by the location of the high pressure line. It
is mounted to the end of the compressor case (Fig. 1).
COMPRESSOR DIAGNOSIS
(1) Verify that refrigerant system is at full charge.
Refer to the Refrigerant Service Procedures section
in this Group. (2) Perform A/C Performance Test. Refer to Heater
and A/C Performance Test section in this Group. (3) If performance is not acceptable, perform ex-
pansion valve tests. Refer to Expansion Valve Tests
in this section. (4) If expansion valve test is correct, refer to the
Variable Displacement Compressor Diagnosis charts.
COMPRESSOR NOISE
Excessive noise that occurs when the air condition-
ing is being used, can be caused by:
² Loose bolts
² Mounting brackets
² Loose clutch
² Excessive high refrigerant system operating pres-
sure Verify compressor drive belt condition, proper re-
frigerant charge and head pressure before compressor
repair is performed. For noise diagnostic procedures, refer to the Com-
pressor Noise and Compressor Clutch Diagnosis
chart in this section.
COMPRESSOR CLUTCH INOPERATIVE
The air conditioning compressor clutch electrical
circuit is controlled by the engine controller. The
controller is located in the engine compartment out-
board of the battery. If the compressor clutch does not engage:
Verify refrigerant charge. Refer to Refrigerant Ser-
vice Procedures in this section. If the compressor clutch still does not engage:
Check for battery voltage at the differential pres-
sure cut-off switch located on the expansion valve. If
voltage is not detected, refer to: (1) Group 8W, Wiring Diagrams.
Fig. 1 Variable Displacement CompressorÐModel 6C17
Ä HEATING AND AIR CONDITIONING 24 - 13

(2) The appropriate Powertrain Diagnostic Proce-
dures Manual for diagnostic information. (3) The Compressor Clutch DiagnosisÐVariable
Displacement Compressor chart in this section. (4) On 2.2 L Turbo III engines, check for battery
voltage at the Thermal Limiter Switch located on the
compressor. If voltage is found at the cut-off and/or thermal
limiter switch, reconnect switch. Then check for bat-
tery voltage between the compressor clutch connector
terminals. If voltage is detected, perform A/C Clutch Coil
Tests. Refer to Clutch Coil Tests in this section.
CLUTCH COIL TESTS
(1) Verify battery state of charge. (Test indicator
in battery should be green). (2) Connect an ammeter (0-10 ampere scale) in se-
ries with the clutch coil terminal. Use a volt meter
(0-20 volt scale) with clip leads measuring voltage
across the battery and A/C clutch. (3) With A/C control in A/C mode and blower at
low speed, start the engine and run at normal idle. (4) The A/C clutch should engage immediately and
the clutch voltage should be within two volts of the
battery voltage. If the A/C clutch does not engage,
test the fusible link. (5) The A/C clutch coil is acceptable if the current
draw is 2.0 to 3.7 amperes at 11.5-12.5 volts at clutch
coil. This is with the work area temperature at 21ÉC
(70ÉF). If voltage is more than 12.5 volts, add electri-
cal loads by turning on electrical accessories until
voltage reads below 12.5 volts. If coil current reads zero, the coil is open and
should be replaced. If the ammeter reading is 4 am-
peres or more, the coil is shorted and should be re-
placed. If the coil voltage is not within two volts of
the battery voltage, test clutch coil feed circuit for
excessive voltage drop.
COMPRESSOR
The A/C compressor may be removed and posi-
tioned without discharging the refrigerant system.
Discharging is not necessary if removing the A/C
compressor clutch/coil assembly, engine, cylinder
head, or generator.
WARNING: REFRIGERANT PRESSURES REMAIN HIGH
EVEN THOUGH THE ENGINE MAY BE TURNED OFF.
BEFORE REMOVING A FULLY CHARGED COMPRES-
SOR, REVIEW THE SAFETY PRECAUTIONS AND
WARNINGS SECTION IN THIS GROUP. DO NOT TWIST
OR KINK THE REFRIGERANT LINES WHEN REMOV-
ING A FULLY CHARGED COMPRESSOR. SAFETY
GLASSES MUST BE WORN.
REMOVAL AND INSTALLATION
(1) Disconnect NEGATIVE battery cable.
(2) Loosen and remove drive belts (Refer to Group
7, Cooling System) and disconnect compressor clutch
wire lead. (3) Remove refrigerant lines from compressor (if
necessary). (4) Remove compressor attaching nuts and bolts
(Fig. 2 or 3).
(5) Remove compressor. If refrigerant lines were
not removed, lift compressor/clutch assembly and tie
it to a suitable component. To install, reverse the preceding operation.
Fig. 2 A/C Compressor Removal and InstallationÐ3.3L Engines
Fig. 3 A/C Compressor Removal and InstallationÐ3.0 L Engine
Ä HEATING AND AIR CONDITIONING 24 - 17