2005 CHRYSLER VOYAGER engine

²a rotary knob for front fan speed selection can
override the automatic controls. LEDs surrounding
the knob show the current setting.
²a rotary knob for control of the rear system
(Three-Zone ATC system only).
²a rotary knob for mode control can override the
automatic controls. LEDs surrounding the knob show
the current setting.
²computer logic which remembers the settings of
the controls when the ignition is turned off and
retains those settings after a restart. If the system is
off when the ignition is turned off it will be off when
the engine is restarted, etc.
²computer logic which provides variable air recir-
culation under high temperature and humidity condi-
tions. Because recirculation is generally accompanied
by increased fan noise, the proportion of recirculated
to outside air gradually approaches full recirculation
over a broad temperature range.
²computer logic which enables additional heat for
diesel equipped vehicles by using a supplemental
engine coolant heater.
REAR CONTROL PANEL
The Three-Zone ATC sytem utilizes a rear control
panel centrally mounted on the headliner which
includes a VF digital display, a rocker control for
temperature and rotary controls for adjustment of
mode and fan speed of the rear heating-A/C system
by intermediate seat passengers.
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 and into the plenum chamber
above the heating, ventilation and air conditioning
(HVAC) housing, then through the evaporator coil.
Air flow can be directed either through or around the
heater core by adjusting the blend door with the tem-
perature control knob on the A/C-heater control
located on instrument panel. The air flow can then
be directed out from the panel, floor and defrost out-
lets 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 selec-
tor 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 system is a blend-
air type system. In a blend-air system, a blend door
controls the amount of conditioned air that is allowed
to flow through, or around, the heater core. The tem-
perature control knob determines the discharge air
temperature by actuating an electric motor, which
operates the blend door. This allows an almost imme-
diate control of the output air temperature of the sys-
tem.
On all models, the outside air intake can be shut
off by pressing the Recirculation button on the A/C-
heater control. This will operate a electric actuated
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.MANUAL SINGLE ZONE
²The temperature control knob enables continu-
ously variable proportioning of the conditioned air.
²The mode control knob enables continuously
variable proportioning of air flow between modes and
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position.
²When the heater-A/C system is off, the HVAC
computer closes the recirculation door to prevent out-
side air from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the A/C-
heater control.
²To reduce humidity for rapid defogging, the A/C
compressor runs automatically in modes from ªmixº
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off button.
24 - 4 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

defogger function will be active for 10 minutes and
can be turned off by a switch press. The defogger will
function while the control is in the ON mode.
²FAN/MODE± The Fan and Mode knobs have
17 manual selectable positions. Manually changing
either of the rotary knobs for mode or fan speed set-
tings makes control of that blower motor manual. If
only one is changed manually, the other remains
under automatic control. Pressing the HI-AUTO/LO-
AUTO rocker switch restores full automatic control.
²BLOWER DELAY TIMER± The word DELAY
is displayed at start-up to signify that the system is
waiting so that cold air will not be blowing. This tells
the operator that it is unnecessary to turn the sys-
tem off, raise the temperature setting or turn the fan
speed setting down to prevent cold air from blowing.
A countdown in minutes and seconds until the engine
is warm enough to begin delivering heat to the pas-
sengers alternates with the DELAY message at 25
second intervals. This countdown is based on actual
measurement of the rate of engine coolant tempera-
ture change. During the delay time, mix mode is
selected and the fan operates at a low speed to keep
the windshield fog free.
²REAR CONTROL (Three-Zone only)± When
the Rear System control knob is moved to the OFF
position, there will be a delay of approximately 1 sec-
ond before the system actually turns off. This delay
is to prevent an undesired blower dropout if the knob
is moved through OFF to the other selections.
REAR CONTROL PANEL ± THREE ZONE ATC
SYSTEM
Primary control of the rear compartment heating-
A/C system for the Three-Zone ATC system is in the
instrument panel center stack. This control allows
the driver to turn the rear heating-A/C system off, or
allows the intermediate seat occupants control of the
rear system by switching to the REAR position, or
provides fully automatic control based on the temper-
ature setting shown on the front control display.
²REAR CONTROL± Selecting automatic control
of the rear unit at the instrument panel, illuminates
a Locked Padlock in the rear control panel display.
Selecting REAR activates the rear control panel and
the Padlock then appears unlocked.
²FAN KNOB± The rear fan control has Off and
AUTO positions and a range of manual speed set-
tings that override the AUTO setting.
²MODE KNOB± The mode control allows inter-
mediate seat occupants to manually override the
automatic mode and select any balance of air flow
between overhead and floor outlets from full over-
head to full floor.
²SET TEMP± The rear set temp control will
operate identical to the front controls. If the frontcontrol rear set temp button is pressed simulta-
neously with the rear control head, then the front
control head press events shall have priority, i.e. if
the front user presses Rear Set Temp down and the
rear user presses Set Temp up, then the rear set
temp will decrease.
DIAGNOSIS AND TESTING
A/C COOL DOWN TEST
The heater-A/C control module can perform an A/C
cool down test, which is a test performed during the
manufacturing process to confirm that the air condi-
tioning system is performing satisfactorily. This test
can also provide a quick confirmation of air condi-
tioning system performance to the service technician.
If the test is completed satisfactorily, no further ser-
vice is required. If the test is failed, proceed to the
A/C Performance Test to confirm the A/C system is
operating properly, or use a DRBIIItscan tool to
diagnose the A/C system control and distribution sys-
tems. Refer to the appropriate diagnostic informa-
tion.
MANUAL TEMPERATURE CONTROL
The front blower speed and rear blower speed (if
equipped with rear HVAC) must be set to High and
the evaporator temperature sensor must be greater
than 13É C (55É F) or the test will fail immediately.
The test is activated by depressing the A/C and Rear
Wipe/Wash buttons simultaneously and holding them
depressed for no less than five seconds. The Rear
Wipe/Wash and A/C LEDs will blink on and off until
the test is complete. If the LEDs stop blinking before
two minutes, then the cool down test has been com-
pleted successfully. If the two minutes expire without
the expansion valve temperature reaching -6É C (20É
F) less than the outside air temperature, then the
cool down test has been failed and further A/C sys-
tem diagnosis is required. If the test is failed, the
LEDs will continue to blink until the vehicle has
been driven for greater than 13 km (8 miles).
AUTOMATIC TEMPERATURE CONTROL
The ambient air temperature in the room where
the vehicle will be tested must be a minimum of 21É
C (70ÉF) for this test. The test is activated by
depressing the A/C and PWR buttons simultaneously
and holding them depressed for no less than four sec-
onds. The snowflake icon and the DELAY text in the
ATC display will blink on and off alternately until
the test is complete. If the snowflake icon and the
DELAY text stop blinking before two minutes, then
the cool down test has been completed successfully. If
the two minutes expire without the evaporator tem-
perature reaching -6É C (20É F) less than the evapo-
24 - 6 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

rator initial temperature, then the cool down test has
been failed and further A/C system diagnosis is
required. If the test is failed, the snowflake icon and
the DELAY text will continue to blink across ignition
cycles until the vehicle has been driven for greater
than 13 km (8 miles).
A/C PERFORMANCE TEST
The A/C system is designed to remove heat and
humidity from the air entering the passenger com-
partment. The evaporator, located in the HVAC hous-
ing, is cooled to temperatures near the freezing point.
As warm damp air passes over the fins in the A/C
evaporator, moisture in the air condenses to water,
dehumidifying the air. Condensation on the evapora-
tor fins reduces the evaporators ability to absorb
heat. During periods of high heat and humidity, an
A/C system will be less effective. With the instru-
ment control set to recirculation mode, only air from
the passenger compartment passes through the A/C
evaporator. As the passenger compartment air dehu-
midifies, 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 A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and tubing. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature 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
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause of
trouble with the A/C system. The ambient air tem-perature in the location where the vehicle will be
tested must be a minimum of 21É C (70É F) for this
test.
PERFORMANCE TEST PROCEDURE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
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.
(2) Set the mode control to the Recirculation Mode
position, the temperature control to the full cool posi-
tion and the blower 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's side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) If the compressor clutch does not engage, pro-
ceed with diagnosis of the compressor clutch coil.
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS - FRONT/COMPRESSOR CLUTCH
COIL - DIAGNOSIS AND TESTING).
(7) With the A/C compressor clutch engaged, com-
pare the air temperature at the center panel outlet
and the compressor discharge pressure to the A/C
Performance Temperature and Pressure chart. The
compressor clutch may cycle, depending upon the
ambient temperature and humidity. If the clutch
cycles, use the readings obtained before the clutch
disengaged.
RSHEATING & AIR CONDITIONING24-7
HEATING & AIR CONDITIONING (Continued)

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 actuator
improperly installed or faulty.2. See Blend Door Actuator in this group. Inspect
the actuator for proper operation and replace, if
required.
3. Blend door inoperative or
sealing improperly.3. See HVAC Housing in this group. Inspect the
blend door for proper operation and sealing.
Repair if required.
4. Blend door not in full cold
position.Use a DRBIII Scan Tool to check for DTCs and
blend door position. Refer to Body Diagnostic
Procedures.
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 A/C evaporator is
restricted.2. See A/C Evaporator in this group. Replace the
restricted A/C evaporator, if required.
3. Faulty A/C compressor. 3. 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. A/C 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. Clean, repair, or replace
components as required.
2. Refrigerant flow through
the receiver/drier is
restricted.2. See Receiver/Drier in this group. Replace the
restricted receiver/drier, if required.
3. Inoperative radiator
cooling fan.3. Test the radiator cooling fan and replace, if
required. Refer to Group 7.
4. Refrigerant system
overcharged.4. See Refrigerant System Charge in this group.
Recover the refrigerant from the refrigerant
system. Charge the refrigerant system to the
proper level, if required.
5. Air in the refrigerant
system.5. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
6. Engine overheating. 6. Test the engine cooling system and repair, if
required. Refer to Group 7.
The low side pressure is too
high, and the high side
pressure is too low.1. Accessory drive belt
slipping.1. Inspect the accessory drive belt condition and
tension. Tighten or replace the accessory drive
belt, if required. Refer to Group 7.
2. Faulty A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Faulty A/C compressor. 3. See A/C Compressor in this group. Replace
the compressor, if required.
RSHEATING & AIR CONDITIONING24-9
HEATING & AIR CONDITIONING (Continued)

Condition Possible Causes Correction
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid Line, Suction Line and Discharge
Line in this group. Inspect the refrigerant lines for
kinks, tight bends or improper routing. Correct
the routing or replace the refrigerant line, if
required.
2. Restricted refrigerant flow
through the A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Restricted refrigerant flow
through the A/C condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
HEATER PERFORMANCE TEST
WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS IN THIS GROUP BEFORE PERFORMING
THIS PROCEDURE (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING).
Check the coolant level, drive belt tension, radiator
air flow and fan operation. Start engine and allow to
warm up to normal operating temperature.
WARNING: DO NOT REMOVE RADIATOR CAP
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
RESULT.
If vehicle has been run recently, wait 15 minutes
before removing the radiator cap. Place a rag overthe cap and turn it to the first safety stop. Allow
pressure to escape through the overflow tube. When
the system pressure stabilizes, remove the cap com-
pletely.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two heater hoses. With the engine idling at normal
operating temperature, set the temperature control
to maximum heat, the mode control to the floor posi-
tion, and the blower in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged from the floor outlets. Com-
pare the test thermometer reading to the Tempera-
ture Reference chart.
TEMPERATURE REFERENCE
Ambient Temperature Minimum Floor Outlet Temperature
Celsius Fahrenheit Celsius Fahrenheit
15.5É 60É 62.2É 144É
21.1É 70É 63.8É 147É
26.6É 80É 65.5É 150É
32.2É 90É 67.2É 153É
If the floor outlet air temperature is insufficient,
check that the cooling system is operating to specifi-
cations (Refer to 7 - COOLING/ENGINE - DIAGNO-
SIS AND TESTING). Both heater hoses should be
HOT to the touch (the coolant return hose should be
slightly cooler than the supply hose). If the coolant
return hose is much cooler than the supply hose,
locate and repair the engine coolant flow obstruction
in heater system.
OBSTRUCTED COOLANT FLOW Possible locations or causes
of obstructed coolant flow are as follows:
²Pinched or kinked heater hoses.
²Improper heater hose routing.²Plugged heater hoses or supply and return ports
at the cooling system connections.
²Plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is insuffi-
cient, a mechanical problem may exist.
MECHANICAL PROBLEMS
Possible causes of insufficient heat due to mechan-
ical problems are as follows:
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend door not functioning properly.
24 - 10 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on the
A/C-heater control panel, the following could require
service:
²Blend door binding.
²Faulty blend door actuator.
²Faulty A/C-heater control.
²Faulty related wiring harness or connectors.²Improper engine coolant temperature.
SPECIFICATIONS
A/C SYSTEM
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood Specifica-
tion Label.
SYSTEM SPECIFICATIONS
Item Description Notes
A/C Compressor Denso 10S17 ± 2.4L/2.5L/2.8L/3.3L
without rear A/C
Denso 10S20 ± 3.3L/3.8L with rear
A/CND-8 PAG Oil
Freeze±up Control Evaporator temperature sensor HVAC housing mounted (RS models),
Evaporator mounted (RG models) - input to
A/C-heater control module
Low PSI Control A/C pressure transducer Liquid line mounted - input to Powertrain Control
Module (PCM) - PCM opens compressor clutch
relay above 200 kPa (29 psi)
High PSI Control A/C pressure transducer Liquid line mounted - input to PCM - PCM
opens compressor clutch relay below 3100 kPa
(450 psi)
High Pressure relief valve Compressor mounted - opens above 3445-4135
kPa (500-600 psi), closes below 2756 kPa (400
psi)
Compressor Clutch Coil
DrawDenso 10S17 ± 3.3 amps @ 12V  
0.5V @ 21É C (70É F)
Denso 10S20 ± 2.2 amps @ 12V  
0.5V @ 21É C (70É F)
Compressor Clutch Air
Gap0.35 - 0.60 mm (0.014 - 0.024 in.)
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft Bolt 17.5 ± 155
A/C Compressor Mounting Bolts (2.4L/2.5L/2.8L) 28 21 ±
A/C Compressor Mounting Bolts (3.3L/3.8L) 54 40 ±
A/C Compressor Mounting Bracket Bolts (2.4L) 54 40 ±
A/C Condenser Mounting Bracket Screws 5 ± 45
A/C Expansion Valve Screws 11 ± 97
A/C-Heater Control Screws 2 ± 17
Blend Door Actuator Screws 2 ± 17
Blower Motor Screws 2 ± 17
Blower Motor Power Module Screws (ATC) 2 ± 17
Blower Motor Resistor Block Screws (MTC) 2 ± 17
Center Bezel Outlet Screws 2 ± 17
RSHEATING & AIR CONDITIONING24-11
HEATING & AIR CONDITIONING (Continued)

CONTROLS - FRONT
TABLE OF CONTENTS
page page
A/C COMPRESSOR CLUTCH/COIL
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING
A/C COMPRESSOR CLUTCH COIL........14
STANDARD PROCEDURE
CLUTCH INSPECTION.................15
A/C CLUTCH BREAK-IN................15
REMOVAL.............................15
INSTALLATION.........................16
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................18
OPERATION...........................18
REMOVAL.............................19
INSTALLATION.........................19
A/C HEATER CONTROL
DESCRIPTION.........................19
STANDARD PROCEDURE
A/C-HEATER CONTROL CALIBRATION.....19
REMOVAL.............................20
INSTALLATION.........................20
A/C PRESSURE TRANSDUCER
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING
A/C PRESSURE TRANSDUCER..........21
REMOVAL.............................21
INSTALLATION.........................21
BLEND DOOR ACTUATOR
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................22
BLOWER MOTOR RELAY
DESCRIPTION.........................23
OPERATION...........................23
REMOVAL.............................24INSTALLATION.........................24
BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION.........................24
OPERATION...........................24
DIAGNOSIS AND TESTING
FRONT BLOWER MOTOR RESISTOR
BLOCK.............................25
REMOVAL.............................25
INSTALLATION.........................25
EVAPORATOR TEMPERATURE SENSOR
DESCRIPTION.........................26
OPERATION...........................27
REMOVAL
RG MODELS.........................27
RS MODELS.........................27
INSTALLATION
RG MODELS.........................27
RS MODELS.........................28
INFRARED TEMPERATURE SENSOR
DESCRIPTION.........................28
OPERATION...........................28
MODE DOOR ACTUATOR
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................29
INSTALLATION.........................30
POWER MODULE - BLOWER MOTOR
DESCRIPTION.........................30
OPERATION...........................30
REMOVAL.............................30
INSTALLATION.........................31
RECIRCULATION DOOR ACTUATOR
DESCRIPTION.........................31
OPERATION...........................31
REMOVAL.............................32
INSTALLATION.........................32
A/C COMPRESSOR CLUTCH/
COIL
DESCRIPTION
The A/C compressor clutch assembly consists of a
stationary electromagnetic A/C clutch field coil with a
zener diode, a pulley bearing and pulley assembly,
and a clutch plate (Fig. 1). These components provide
the means to engage and disengage the A/C compres-
sor from the engine accessory drive belt.The A/C clutch field coil and the pulley bearing
and pulley assembly are both retained on the nose of
the A/C compressor with snap rings. The clutch plate
is splined to the compressor shaft and secured with a
bolt.
OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
RSCONTROLS - FRONT24-13

clutch plate into contact with the clutch pulley and
drives the compressor shaft. When the coil is not
energized, the pulley freewheels on the clutch hub
bearing, which is part of the pulley.
A zener diode is connected in parallel with the
clutch electromagnetic coil. This diode controls the
dissipation of voltage induced into the coil windings
by the collapsing of the electromagnetic fields that
occurs when the compressor clutch is disengaged.
The zener diode dissipates this induced voltage by
regulating a current path to ground. This arrange-
ment serves to protect other circuits and components
from potentially damaging voltage spikes in the vehi-
cle electrical system that might occur if the voltage
induced in the clutch coil windings could not be dis-
sipated.
The compressor clutch engagement is controlled by
several components: the heater-A/C controls in the
passenger compartment, the A/C pressure transducer
on the liquid line, the evaporator temperature sensor
on the expansion valve for automatic temperature
control (ATC) system or on the HVAC housing for
manual temperature control (MTC) system, the Pow-
ertrain Control Module (PCM) in the engine compart-
ment, and the compressor clutch relay in the
Integrated Power Module (IPM). The PCM may delay
compressor clutch engagement for up to thirty sec-
onds (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN CONTROL
MODULE - DESCRIPTION - PCM OPERATION).
DIAGNOSIS AND TESTING
A/C COMPRESSOR CLUTCH COIL
The air conditioning compressor clutch coil electri-
cal circuit is controlled by the powertrain control
module (PCM) through the A/C compressor clutch
relay, which is located in the integrated power mod-
ule (IPM) in the engine compartment. Begin testing
of a suspected compressor clutch coil problem by per-
forming the preliminary checks.
PRELIMINARY CHECKS
(1) If the compressor clutch will not engage, verify
the refrigerant charge level (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - FRONT/RE-
FRIGERANT - DIAGNOSIS AND TESTING -
REFRIGERANT CHARGE LEVEL). If the refriger-
ant charge level is OK, go to Step 2. If the refriger-
ant charge level is not OK, adjust the refrigerant
charge as required.
(2) If the A/C compressor clutch still will not
engage, disconnect the wire harness connector for the
A/C pressure transducer and check for battery cur-
rent at the connector with the engine running and
the A/C-heater control set to the A/C mode. If OK, go
to TESTS. If not OK, refer to Body Diagnostic Proce-
dures to perform further diagnosis.
TESTS
(1) Verify the battery state of charge (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/BATTERY -
DIAGNOSIS AND TESTING).
(2) Connect an ammeter (0 to 10 ampere scale
selected) in series with the clutch coil feed terminal.
Connect a voltmeter (0 to 20 volt scale selected) to
measure voltage across the battery and the clutch
coil.
(3) With the heater-A/C control in the A/C mode
and the blower at low speed, start the engine and
allow it to run at a normal idle speed.
(4) The compressor clutch should engage immedi-
ately, and the clutch coil voltage should be within
two volts of the battery voltage. If the coil voltage is
not within two volts of battery voltage, test the
clutch coil feed circuit for excessive voltage drop. If
the compressor clutch does not engage, refer to Body
Diagnostic Procedures to perform further diagnosis.
(5) For the acceptable A/C clutch coil current draw
specificationsrefer to 24 - HEATING & AIR CONDI-
TIONING - SPECIFICATIONS. Specifications apply
for a work area temperature of 21É C (70É F). If volt-
age is more than 12.5 volts, add electrical loads by
turning on electrical accessories until voltage reads
below 12.5 volts.
(a) If the compressor clutch coil current reading
is zero, the coil is open and must be replaced.
Fig. 1 A/C Compressor Clutch
1 - BOLT
2 - CLUTCH PLATE
3 - PULLEY AND BEARING
4 - FIELD COIL
5 - SNAP RING (2)
6 - SHIM
24 - 14 CONTROLS - FRONTRS
A/C COMPRESSOR CLUTCH/COIL (Continued)