clutch CHRYSLER VOYAGER 2001 Service Manual

CONTROLS - FRONT
TABLE OF CONTENTS
page page
A/C-HEATER CONTROL
STANDARD PROCEDURE...................8
HEATER-A/C CONTROL CALIBRATION.......8
REMOVAL...............................9
INSTALLATION............................9
A/C PRESSURE TRANSDUCER
DESCRIPTION...........................10
OPERATION.............................10
DIAGNOSIS AND TESTING.................10
A/C PRESSURE TRANSDUCER............10
REMOVAL..............................11
INSTALLATION...........................11
BLEND DOOR ACTUATOR
DESCRIPTION...........................11
OPERATION.............................12
REMOVAL..............................12
INSTALLATION...........................12
BLOWER MOTOR RELAY
DESCRIPTION...........................13
OPERATION.............................14
DIAGNOSIS AND TESTING.................14
BLOWER MOTOR RELAY.................14
REMOVAL..............................14
INSTALLATION...........................14
BLOWER MOTOR RESISTOR
DESCRIPTION...........................15
OPERATION.............................15
DIAGNOSIS AND TESTING.................15
BLOWER MOTOR RESISTOR.............15
REMOVAL..............................16
INSTALLATION...........................16
COMPRESSOR CLUTCH
DESCRIPTION...........................17
OPERATION.............................17
STANDARD PROCEDURE..................18
COMPRESSOR CLUTCH AIR GAP..........18
COMPRESSOR CLUTCH BREAK-IN.........18REMOVAL..............................18
INSPECTION............................19
INSTALLATION...........................20
COMPRESSOR CLUTCH COIL
DIAGNOSIS AND TESTING.................21
COMPRESSOR CLUTCH COIL.............21
COMPRESSOR CLUTCH RELAY
DESCRIPTION...........................21
OPERATION.............................22
DIAGNOSIS AND TESTING.................22
COMPRESSOR CLUTCH RELAY...........22
REMOVAL..............................23
INSTALLATION...........................23
EVAPORATOR TEMPERATURE SENSOR
DESCRIPTION...........................23
OPERATION.............................23
REMOVAL..............................24
INSTALLATION...........................24
INFRARED TEMPERATURE SENSOR
DESCRIPTION...........................24
OPERATION.............................25
MODE DOOR ACTUATOR
DESCRIPTION...........................25
OPERATION.............................25
REMOVAL..............................26
INSTALLATION...........................26
POWER MODULE
DESCRIPTION...........................26
OPERATION.............................27
REMOVAL..............................27
INSTALLATION...........................27
RECIRCULATION DOOR ACTUATOR
DESCRIPTION...........................28
OPERATION.............................28
REMOVAL..............................29
INSTALLATION...........................29
A/C-HEATER CONTROL
STANDARD PROCEDURE - HEATER-A/C
CONTROL CALIBRATION
The heater-A/C control module must be recali-
brated each time an actuator motor or the control
module is replaced. This is necessary so that the con-
trol module can ªlearnº the feedback voltages for
each actuator motor at both stop positions of each
door in the front HVAC unit housing. If the vehicle isso equipped, the calibration procedure also includes
rear HVAC positions for each actuator motor.
(1) Turn the ignition switch to the On position.
(2) Simultaneously depress and hold the Power
and Recirculation buttons on the heater-A/C control
for at least five seconds. The manual heater-A/C con-
trol Delay Light Emitting Diode (LED) and Recircu-
lation LED, or the Automatic Temperature Control
(ATC) heater-A/C control Delay and Recirculation
graphics will begin to flash when the calibration pro-
cedure has begun.
24 - 8 CONTROLS - FRONTRS

A/C PRESSURE TRANSDUCER
DESCRIPTION
The A/C pressure transducer (Fig. 2) is a switch
that is installed on a fitting located on the refriger-
ant liquid line between the filter-drier and the
expansion valve in the right rear corner of the engine
compartment. An internally threaded hex fitting on
the transducer connects it to the externally threaded
Schrader-type fitting on the liquid line. A rubber
O-ring seals the connection between the transducer
and the liquid line fitting. Three terminals within a
molded plastic connector receptacle on the top of the
transducer connect it to the vehicle electrical system
through a take out and connector of the headlamp
and dash wire harness.
The A/C pressure transducer cannot be adjusted or
repaired and, if faulty or damaged, it musty be
replaced.
OPERATION
The A/C pressure transducer monitors the pres-
sures in the high side of the refrigerant system
through its connection to a fitting on the liquid line.
The transducer will change its internal resistance in
response to the pressures it monitors. The Power-
train Control Module (PCM) provides a five volt ref-
erence signal and a sensor ground to the transducer,
then monitors the output voltage of the transducer
on a sensor return circuit to determine refrigerant
pressure. The PCM is programmed to respond to thisand other sensor inputs by controlling the operation
of the air conditioning compressor clutch and the
radiator cooling fan to help optimize air conditioning
system performance and to protect the system com-
ponents from damage. The A/C pressure transducer
input to the PCM will also prevent the air condition-
ing compressor clutch from engaging when ambient
temperatures are below about 10É C (50É F) due to
the pressure/temperature relationship of the refriger-
ant. The Schrader-type valve in the liquid line fitting
permits the A/C pressure transducer to be removed
or installed without disturbing the refrigerant in the
system. The A/C pressure transducer is diagnosed
using a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER
The A/C pressure transducer is tested using a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information. Before testing the A/C pressure
transducer, be certain that the transducer wire har-
ness connection is clean of corrosion and properly
connected. For the air conditioning system to operate,
an A/C pressure transducer voltage reading between
0.451 and 4.519 volts is required. Voltages outside
this range indicate a low or high refrigerant system
pressure condition to the Powertrain Control Module
(PCM). The PCM is programmed to respond to a low
or high refrigerant system pressure by suppressing
operation of the compressor. Refer to the A/C Pres-
sure Transducer Voltage table for the possible condi-
tion indicated by the transducer voltage readings.
A/C PRESSURE TRANSDUCER VOLTAGE
VOLTAGE POSSIBLE INDICATION
0.0 1. NO SENSOR SUPPLY
VOLTAGE FROM PCM.
2. SHORTED SENSOR CIRCUIT.
3. FAULTY TRANSDUCER.
0.150 TO 0.450 1. AMBIENT TEMPERATURE
BELOW 10É C (50É F).
2. LOW REFRIGERANT
SYSTEM PRESSURE.
0.451 TO 4.519 1. NORMAL REFRIGERANT
SYSTEM PRESSURE.
4.520 TO 4.850 1. HIGH REFRIGERANT
SYSTEM PRESSURE.
5.0 1. OPEN SENSOR CIRCUIT.
2. FAULTY TRANSDUCER.
Fig. 2 A/C Pressure Transducer
1 - RIGHT FRONT STRUT TOWER
2 - CONNECTOR
3 - A/C PRESSURE TRANSDUCER
4 - RIGHT WIPER MODULE DRAIN TUBE
5 - HIGH SIDE SERVICE PORT
6 - LIQUID LINE
24 - 10 CONTROLS - FRONTRS

(2) Install and tighten the two screws that secure
the blower motor resistor to the evaporator housing.
Tighten the screws to 2 N´m (17 in. lbs.).
(3) Reconnect the blower motor pigtail wire con-
nector to the blower motor resistor connector recep-
tacle.
(4) Reconnect the instrument panel wire harness
connector for the blower motor resistor to the resistor
connector receptacle.
(5) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box upward.
(6) Close and latch the glove box.
(7) Reconnect the battery negative cable.
COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil with a zener diode, a hub
bearing and pulley assembly, and a clutch plate (Fig.
12). The electromagnetic coil unit and the hub bear-
ing and pulley assembly are each retained on the
nose of the compressor front housing with snap rings.
The clutch plate is keyed or splined to the compres-
sor shaft, and secured with a bolt.
The compressor clutch plate and pulley unit, or the
clutch coil are available for separate service replace-
ment. The clutch coil zener diode is integral to the
clutch coil pigtail wire and connector and, if faulty ordamaged, the clutch electromagnetic coil unit must
be replaced.
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
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, the Powertrain Control Mod-
ule (PCM) in the engine compartment, and the com-
pressor clutch relay in the Intelligent Power Module
(IPM). The PCM may delay compressor clutch
engagement for up to thirty seconds. (Refer to 8 -
Fig. 11 Blower Motor Resistor
1 - BLOWER MOTOR RESISTOR
2 - INSTRUMENT PANEL WIRE HARNESS
3 - SCREW (2)
4 - GLOVE BOX OPENING LOWER REINFORCEMENT
5 - BLOWER MOTOR PIGTAIL WIRE
6 - EVAPORATOR HOUSING
Fig. 12 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (SOME MODELS)
3 - PULLEY AND BEARING
4 - CLUTCH COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
RSCONTROLS - FRONT24-17
BLOWER MOTOR RESISTOR (Continued)

ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION - PCM OPERATION).
STANDARD PROCEDURE - COMPRESSOR
CLUTCH AIR GAP
If a new clutch plate and/or clutch pulley are being
used, the air gap between the clutch plate and clutch
pulley must be checked using the following proce-
dure:
(1) Using feeler gauges, measure the air gap
between the clutch plate and the clutch pulley fric-
tion surfaces.
(2) If the air gap is not between 0.5 and 0.9 mm
(0.020 and 0.035 in.), add or subtract shims until the
desired air gap is obtained.
NOTE: The shims may compress after tightening
the compressor shaft bolt. Check the air gap in four
or more places on the clutch plate to verify that the
air gap is still correct. Spin the clutch pulley before
making the final air gap check.
STANDARD PROCEDURE - COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
check that the compressor clutch coil is performing to
specifications. (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS - FRONT/COMPRESSOR
CLUTCH COIL - DIAGNOSIS AND TESTING). If
the clutch coil is performing to specifications, per-
form the compressor clutch break-in procedure. This
procedure (burnishing) will seat the opposing friction
surfaces and provide a higher compressor clutch
torque capability.
(1) Set the heater-A/C controls to the A/C mode,
with the blower switch in the highest speed position.
(2) Start the engine and hold the engine speed at
1500 to 2000 rpm.
(3) Cycle the compressor clutch On and Off about
twenty times (five seconds On, then five seconds Off).
REMOVAL
The refrigerant system can remain fully charged
during compressor clutch, pulley, or coil replacement.
Although the compressor assembly must be removed
from its mounting, the compressor clutch can be ser-
vice with the compressor in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Raise and support the vehicle.
(3) Remove the serpentine drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
2.4L - REMOVAL) or (Refer to 7 - COOLING/ACCES-SORY DRIVE/DRIVE BELTS - 3.3/3.8L - REMOV-
AL).
(4) Disconnect the engine wire harness connector
for the compressor clutch coil from the clutch coil pig-
tail wire connector on the top of the compressor.
(5) On models with the 3.3L and 3.8L engines, dis-
engage the retainer on the engine wire harness com-
pressor clutch coil take out from the bracket on the
top of the compressor.
(6) On models with the 2.4L engine, remove all of
the compressor mounting screws except the upper
left (rear of the compressor) screw, which should only
be loosened. Allow the front (pulley end) of the com-
pressor to tilt downward far enough to access the
clutch for removal, then tighten the loosened upper
left compressor mounting screw.
(7) On models with the 3.3L and 3.8L engines,
remove the three screws and one nut that secure the
compressor to the engine. Disengage the mounting
ear at the front of the compressor from the stud on
the engine, allow the front (pulley end) of the com-
pressor to tilt downward far enough to access the
clutch for removal, then reinstall and tighten the
upper left compressor mounting screw.
(8) Remove the compressor shaft bolt (Fig. 13). If
necessary, a band-type oil filter wrench or a strap
wrench can be placed around the clutch plate to aid
in bolt removal.
(9) Tap the clutch plate lightly with a plastic ham-
mer and remove the clutch plate and shim(s) from
Fig. 13 Compressor Shaft Bolt and Clutch Plate
1 - COMPRESSOR SHAFT BOLT
2 - COMPRESSOR CLUTCH PLATE
24 - 18 CONTROLS - FRONTRS
COMPRESSOR CLUTCH (Continued)

the compressor shaft (Fig. 14).Be certain not to
lose the shim or shims.
CAUTION: Do not pry between the clutch plate unit
and the pulley to remove the clutch plate from the
compressor shaft as this may damage the clutch
plate.
(10) Using snap ring pliers (Special Tool C-4574 or
equivalent), remove the external snap ring that
secures the pulley to the front cover of the compres-
sor, then slide the pulley off of the compressor (Fig.
15).
(11) Remove the screw that secures the clutch coil
pigtail wire connector bracket and ground clip to the
top of the compressor housing.
(12) Using snap ring pliers (Special Tool C-4574 or
equivalent), remove the external snap ring that
secures the clutch coil to the front cover of the com-
pressor housing, then slide the clutch coil off of the
compressor (Fig. 16).
INSPECTION - COMPRESSOR CLUTCH/COIL
Compressor clutch components should always be
inspected closely before they are reinstalled. The
clutch plate and clutch pulley are mated at the fac-
tory using a burnishing operation. No attempt should
be made to separately replace the compressor clutch
pulley or clutch plate. The clutch coil may be serviced
separately.
(1) Examine the friction surfaces of the clutch pul-
ley and the clutch plate for wear. The clutch pulley
and clutch plate should be replaced if there is exces-
sive wear or scoring.
(2) Examine the friction surfaces of the clutch pul-
ley and the clutch plate for oil contamination. If thefriction surfaces are oily, the clutch pulley and clutch
plate should be replaced. Also inspect the shaft and
nose area of the compressor for oil. Remove the felt
Fig. 14 Clutch Plate and Shim(s)
1 - COMPRESSOR SHAFT
2 - CLUTCH PLATE
3 - CLUTCH PLATE SHIM
Fig. 15 Remove Clutch Pulley Snap Ring
1 - SNAP RING
Fig. 16 Remove Clutch Coil Snap Ring
1 - SNAP RING PLIERS
2 - CLUTCH COIL
3 - COMPRESSOR
4 - SNAP RING
RSCONTROLS - FRONT24-19
COMPRESSOR CLUTCH (Continued)

packing from around the compressor shaft in the
compressor front cover. If the felt is saturated with
oil, the compressor front shaft seal is leaking and the
compressor will also have to be replaced.
(3) Check the clutch pulley bearing for roughness
or excessive leakage of grease. Replace the clutch
pulley and clutch plate if the bearing is faulty.
INSTALLATION
The refrigerant system can remain fully charged
during compressor clutch, pulley, or coil replacement.
Although the compressor assembly must be removed
from its mounting, the compressor clutch can be ser-
vice with the compressor in the vehicle.
(1) Align the dowel pin on the back of the clutch
coil with the hole in the compressor front cover, and
position the clutch coil onto the compressor. Be cer-
tain that the clutch coil pigtail wires are properly ori-
ented and routed so that they are not pinched
between the compressor front cover and the clutch
coil.
NOTE: A new snap ring must be used to secure the
clutch coil to the compressor. The bevel side of the
snap ring must face outward.
(2) Using snap ring pliers (Special Tool C-4574 or
equivalent), install the external snap ring that
secures the clutch coil to the front cover of the com-
pressor (Fig. 16). The bevel side of the snap ring
must face outward and both snap ring eyelets must
be oriented to the right or the left of the clutch coil
dowel pin location on the compressor. Be certain that
the snap ring is fully and properly seated in the
groove.
CAUTION: If the snap ring is not fully seated in the
groove it will vibrate out, resulting in a clutch fail-
ure and severe damage to the compressor front
cover.
(3) Install and tighten the screw that secures the
clutch coil pigtail wire connector bracket and ground
clip to the top of the compressor housing.
(4) Install the pulley onto the front cover of the
compressor. If necessary, tap the pulley gently with a
block of wood placed on the pulley friction surface
(Fig. 17).
CAUTION: Do not mar the friction surfaces of the
pulley.
NOTE: A new snap ring must be used to secure the
clutch pulley to the compressor. The bevel side of
the snap ring must face outward.(5) Using snap ring pliers (Special Tool C-4574 or
equivalent), install the external snap ring (bevel side
facing outward) that secures the clutch pulley to the
front cover of the compressor (Fig. 15). Be certain
that the snap ring is fully and properly seated in the
groove.
(6) If the original clutch plate and clutch pulley
are to be reused, reinstall the original shim(s) on the
compressor shaft against the shoulder (Fig. 14). If a
new clutch plate and/or clutch pulley are being used,
install a trial stack of shims 1.0 mm (0.040 in.) thick
on the compressor shaft against the shoulder.
(7) Install the clutch plate onto the compressor
shaft.
(8) Install and tighten the compressor shaft nut
(Fig. 13). If necessary, a band-type oil filter wrench
or a strap wrench can be placed around the clutch
plate to aid in bolt tightening. Tighten the bolt to
17.5 N´m (155 in. lbs.).
(9) If a new clutch plate and/or clutch pulley are
being installed, the air gap between the clutch plate
and clutch pulley must be checked. (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS -
FRONT/COMPRESSOR CLUTCH - STANDARD
PROCEDURE - COMPRESSOR CLUTCH AIR GAP).
(10) On models with the 2.4L engine only, loosely
install the four screws that secure the compressor to
the mounting bracket on the engine. Tighten the
screws to 28 N´m (21 ft. lbs.).
Fig. 17 Install Clutch Pulley
1 - PULLEY ASSEMBLY
2 - WOOD BLOCK
24 - 20 CONTROLS - FRONTRS
COMPRESSOR CLUTCH (Continued)

(11) On models with the 3.3L and 3.8L engines
only, loosely install the three screws and one nut that
secure the compressor to the engine. Tighten each of
the fasteners using the following sequence to 54 N´m
(40 ft. lbs.).
²The upper screw at the rear of the compressor.
²The lower screw at the rear of the compressor.
²The lower screw at the front of the compressor.
²The upper nut at the front of the compressor.
(12) On models with the 3.3L and 3.8L engines
only, engage the retainer on the engine wire harness
compressor clutch coil take out with the bracket on
the top of the compressor.
(13) Reconnect the engine wire harness connector
for the compressor clutch coil to the coil pigtail wire
connector on the top of the compressor.
(14) Reinstall the serpentine accessory drive belt
onto the front of the engine. (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - 2.4L -
INSTALLATION) or (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - 3.3L/3.8L - INSTAL-
LATION).
(15) Lower the vehicle.
(16) Reconnect the battery negative cable.
(17) If a new clutch plate and/or clutch pulley are
being installed, the new clutch components must be
burnished. (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS - FRONT/COMPRESSOR
CLUTCH - STANDARD PROCEDURE - COMPRES-
SOR CLUTCH BREAK-IN).
COMPRESSOR CLUTCH COIL
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL
The air conditioning compressor clutch coil electri-
cal circuit is controlled by the Powertrain Control
Module (PCM) through the compressor clutch relay,
which is located in the Intelligent Power Module
(IPM) in the engine compartment near the battery.
Begin testing of a suspected compressor clutch coil
problem by performing 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 headlamp and dash wire har-
ness connector for the A/C pressure transducer andcheck for battery current at the connector with the
engine running and the heater-A/C control set to the
A/C mode. If OK, go to TESTS . If not OK, use a
DRBIIItscan tool to perform further diagnosis. Refer
to the appropriate diagnostic information.
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, use a
DRBIIItscan tool to perform further diagnosis. Refer
to the appropriate diagnostic information.
(5) With the ambient temperature at 21É C (70É F),
the compressor clutch coil is acceptable if the current
draw is 2.0 to 3.7 amperes at 11.5 to 12.5 volts at the
clutch coil. If the voltage is more than 12.5 volts, add
electrical loads by turning on electrical accessories
until the voltage reads below 12.5 volts.
(a) If the compressor clutch coil current reading
is zero, the coil is open and must be replaced.
(b) If the compressor clutch coil current reading
is four amperes or more, the coil is shorted and
must be replaced.
COMPRESSOR CLUTCH RELAY
DESCRIPTION
The compressor clutch relay (Fig. 18) is a Interna-
tional Standards Organization (ISO) micro-relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The ISO
micro-relay terminal functions are the same as a con-
ventional ISO relay. However, the ISO micro-relay
terminal pattern (or footprint) is different, the cur-
rent capacity is lower, and the physical dimensions
are smaller than those of the conventional ISO relay.
The compressor clutch relay is located in the Intelli-
gent Power Module (IPM), which is in the engine
compartment near the battery. See the fuse and relay
layout map molded into the inner surface of the IPM
RSCONTROLS - FRONT24-21
COMPRESSOR CLUTCH (Continued)

cover for compressor clutch relay identification and
location.
The black, molded plastic case is the most visible
component of the compressor clutch relay. Five male
spade-type terminals extend from the bottom of the
base to connect the relay to the vehicle electrical sys-
tem, and the ISO designation for each terminal is
molded into the base adjacent to each terminal. Refer
to (Fig. 8)
OPERATION
The compressor clutch relay is an electromechani-
cal switch that uses a low current input from the
Powertrain Control Module (PCM) to control the high
current output to the compressor clutch electromag-
netic coil. The movable common feed contact point is
held against the fixed normally closed contact point
by spring pressure. When the relay coil is energized,
an electromagnetic field is produced by the coil wind-
ings. This electromagnetic field draws the movable
relay contact point away from the fixed normally
closed contact point, and holds it against the fixed
normally open contact point. When the relay coil is
de-energized, spring pressure returns the movable
contact point back against the fixed normally closed
contact point. The resistor or diode is connected in
parallel with the relay coil in the relay, and helps to
dissipate voltage spikes and electromagnetic interfer-
ence that can be generated as the electromagnetic
field of the relay coil collapses.
The compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the Intelligent Power Module (IPM).
The inputs and outputs of the 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 (85) receives a ground
input from the PCM through the compressor clutch
relay control circuit only when the PCM electroni-
cally pulls the control circuit to ground.²The coil battery terminal (86) receives a battery
current input from the PCM through a fused ignition
switch output (run-start) circuit only when the igni-
tion switch is in the On or Start positions.
²The normally open terminal (87) provides a bat-
tery current output to the compressor clutch coil
through the compressor clutch relay output circuit
only when the compressor clutch relay coil is ener-
gized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the compressor
clutch relay coil is de-energized.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY
The compressor clutch relay (Fig. 18) is located in
the Intelligent Power Module (IPM), which is in the
engine compartment near the battery. See the fuse
and relay layout map molded into the inner surface
of the IPM cover for compressor clutch relay identifi-
cation and location. Remove the relay from the IPM
to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 7565 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, use a DRBIIItscan tool to perform
further diagnosis of the relay circuits. Refer to the
appropriate diagnostic information. If not OK,
replace the faulty relay.
24 - 22 CONTROLS - FRONTRS
COMPRESSOR CLUTCH RELAY (Continued)

TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Intelli-
gent Power Module (IPM).
(3) See the fuse and relay layout map molded into
the inner surface of the IPM cover for compressor
clutch relay identification and location.
(4) Remove the compressor clutch relay from the
IPM by pulling it straight up.
INSTALLATION
(1) See the fuse and relay layout map molded into
the inner surface of the Intelligent Power Module
(IPM) cover for compressor clutch relay identification
and location.
(2) Position the compressor clutch relay to the
proper receptacle in the IPM.
(3) Align the compressor clutch relay terminals
with the terminal cavities in the IPM relay recepta-
cle.(4) Push down firmly on the compressor clutch
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install and latch the cover onto the IPM.
(6) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a switch that
is installed on the top of the expansion valve in the
right rear corner of the engine compartment (Fig.
19). The sensor has a small probe that is inserted in
a small well in the body of the expansion valve that
is filled with a special silicone-based thermal grease.
A small molded plastic push-in retainer secures the
sensor to a threaded hole in the top surface of the
expansion valve. Two terminals within a molded
plastic connector receptacle on the sensor connect it
to the vehicle electrical system through a take out
and connector of the HVAC wire harness.
The evaporator temperature sensor cannot be
adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
The evaporator temperature sensor monitors the
temperature of the evaporator through its connection
to the top of the expansion valve. The sensor will
change its internal resistance in response to the tem-
Fig. 18 Compressor Clutch Relay
1 - RELAY TERMINALS
2 - RELAY CAVITIES
Fig. 19 Evaporator Temperature Sensor
1 - RIGHT FRONT STRUT TOWER
2 - EVAPORATOR TEMPERATURE SENSOR
3 - EXPANSION VALVE
4 - DASH PANEL
5 - RETAINER
RSCONTROLS - FRONT24-23
COMPRESSOR CLUTCH RELAY (Continued)

peratures it monitors. The heater-A/C control module
is connected to the sensor through a sensor ground
circuit and a sensor signal circuit. As the evaporator
temperature increases, the resistance of the sensor
decreases and the voltage monitored by the module
decreases. The module uses this monitored voltage
reading to an indication of the evaporator tempera-
ture. The heater-A/C control module is programmed
to respond to this input by sending electronic mes-
sages to the Powertrain Control Module (PCM) over
the Programmable Communications Interface (PCI)
data bus, and the PCM then cycles the air condition-
ing compressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing. The external loca-
tion of the sensor and the use of a push-in plastic
retainer allows the sensor to be removed or installed
from the expansion valve without disturbing the
refrigerant in the system. The evaporator tempera-
ture sensor is diagnosed using a DRBIIItscan tool.
Refer to the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the air cleaner housing from the right
side of the engine compartment.
(3) Remove the windshield wiper assembly from
the vehicle (Refer to 8 - ELECTRICAL/WIPERS/
WASHERS/WIPER MODULE - REMOVAL).
(4) Remove the temperature sensor attaching
screw from the expansion valve.
(5) Pull the evaporator temperature sensor away
from the expansion valve far enough to access the
red release ring on the wiring connector. Push the
red ring toward the connector to release lock and
remove the HVAC wire harness connector from the
temperature sensor.
(6) Remove the evaporator temperature sensor
from the engine compartment. Please note that any
grease removed with the old temperature sensor
must be replaced, failure to do so could result in poor
a/c performance.
INSTALLATION
(1) Position the evaporator temperature sensor
into the right rear corner of the engine compartment.
(2) Reconnect the HVAC wire harness connector
for the evaporator temperature sensor to the sensor
connector receptacle.
(3) Position the evaporator temperature sensor
onto the top of the expansion valve with the sensor
probe inserted into the well in the expansion valve
(Fig. 19).
(4) Install the temperature sensor retaining screw
and tighten.(5) Install the window wiper assembly to the vehi-
cle (REFER to 8 - ELECTRICAL/WIPERS/WASH-
ERS/WIPER MODULE - INSTALLATION).
(6) Reinstall the air cleaner housing into the right
side of the engine compartment.
(7) Reconnect the battery negative cable.
INFRARED TEMPERATURE
SENSOR
DESCRIPTION
The infrared temperature sensor consists of two
infrared transducers that are concealed behind a
clear lens located near the bottom of the center panel
outlet near the top of the instrument panel center
bezel (Fig. 20). These sensors are used only on mod-
els equipped with the optional Automatic Tempera-
ture Control (ATC) heating and air conditioning
system. A molded plastic connector receptacle on the
bottom of the panel outlet unit is concealed behind
the center bezel. A short, dedicated jumper wire har-
ness routed behind the center bezel connects the sen-
sors directly to the ATC heater-A/C control module
near the bottom of the center bezel. The infrared
temperature sensor is integral to the center bezel
panel outlet unit. The infrared sensors cannot be
adjusted or repaired and, if faulty or damaged, the
center bezel panel outlet unit must be replaced.
Fig. 20 Infrared Temperature Sensor
1 - INSTRUMENT PANEL CENTER BEZEL
2 - CENTER BEZEL OUTLETS
3 - INFRARED TEMPERATURE SENSOR
24 - 24 CONTROLS - FRONTRS
EVAPORATOR TEMPERATURE SENSOR (Continued)