2004 CHRYSLER VOYAGER engine

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 1.6 km (8 miles).
DIAGNOSIS AND TESTING - 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.
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.
DIAGNOSIS AND TESTING - 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.
24 - 10 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

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.
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 - 10S20 (2.5L/3.3L/3.8L engines)
Denso - 10S17 (2.4L engine)ND-8 PAG Oil
Freeze±up Control Evaporator temperature sensor Expansion valve mounted (ATC),
HVAC housing mounted (MTC)-
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 Draw 2.2 amps @ 12V   0.5V @ 21É C (70É F)
Compressor Clutch Air Gap 0.35 - 0.60 mm (0.014 - 0.025 in.)
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft
Bolt17.5 ± 155
A/C Compressor Mounting
Bolts (2.4L/2.5L)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 Screws5±45
RSHEATING & AIR CONDITIONING24-11
HEATING & AIR CONDITIONING (Continued)

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). A/C clutch field coil and
the pulley bearing 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 compressor shaft, and secured with a nut or
bolt (depending on application). These components
provide the means to engage and disengage the com-
pressor from the engine serpentine accessory drive
belt.
The A/C compressor clutch and coil are available
for separate service replacement. The clutch coil
zener diode is integral to the clutch coil pigtail wire
and connector and, if faulty or damaged, the clutch
electromagnetic coil 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 windingsby 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).
Fig. 1 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 - FRONT24-15

(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) Refer to the A/C Clutch Coil Current Draw
chart for the acceptable A/C clutch coil current draw
specifications. Specifications apply for a work area
temperature of 21É C (70É F). If voltage is more than
12.5 volts, add electrical loads by turning on electri-
cal 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.
(b) If the compressor clutch coil current reading
is four amperes or more, the coil is shorted and
must be replaced.
A/C CLUTCH COIL CURRENT DRAW
Compressor Current Draw
Nippondenso - 10S20
(2.5L/3.3L/3.8L engines)
Nippondenso - 10S17
(2.4L engine)2.2 amps @ 11.5 - 12.5
volts
REMOVAL
NOTE: The compressor clutch can be serviced in
the vehicle. The refrigerant system can remain fully-
charged during compressor clutch, pulley, or coil
replacement.
(1) Disconnect and isolate the battery negative
cable.
(2) 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 -
REMOVAL).
(3) Raise and support the vehicle.
(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 and 2.5L engines,
remove all of the compressor mounting bolts except
the upper left (rear of the compressor), which should
only be loosened. Allow the front (pulley end) of the
compressor to tilt downward far enough to access the
clutch for removal, then tighten the loosened upper
left compressor mounting bolt.
(7) On models with the 3.3L and 3.8L engines,
remove the two bolts and two nuts 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 bolt.
(8) Remove the compressor shaft bolt (Fig. 2). A
band-type oil filter wrench or a strap wrench may be
used to secure the clutch during bolt removal.
(9) Tap the clutch plate lightly with a plastic mal-
let to release it from the splines on the compressor
shaft. Remove the clutch plate and shim(s) from the
compressor shaft (Fig. 3).
NOTE: Use care not to lose any of the shim(s).
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.
Fig. 2 Compressor Shaft Bolt and Clutch Plate
1 - COMPRESSOR SHAFT BOLT
2 - COMPRESSOR CLUTCH PLATE
24 - 16 CONTROLS - FRONTRS
A/C COMPRESSOR CLUTCH/COIL (Continued)

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. 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 securely 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. 6).
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. 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. 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.
NOTE: The shims may compress after tightening
the shaft bolt. Check the air gap in four or more
places to verify the air gap is still correct. Spin the
pulley before performing a final check of the air
gap.
(8) With the clutch plate assembly tight against
the shim(s), measure the air gap between the clutch
plate and the pulley face with feeler gauges. The air
gap should be between 0.35 - 0.60 mm (0.014 - 0.024
in.). If the proper air gap is not obtained, add or sub-
tract shims as needed until the desired air gap is
obtained.
(9) Install the compressor shaft bolt. Tighten the
bolt to 17.5 N´m (155 in. lbs.).
(10) On models with the 2.4L and 2.5L engines,
loosely install the four bolts that secure the compres-
sor to the mounting bracket on the engine (2.4L), or
the cylinder block (2.5L). Tighten the bolts to 28 N´m
(21 ft. lbs.).
(11) On models with the 3.3L and 3.8L engines,
loosely install the two bolts and two nuts that secure
the compressor to the engine. Tighten each of the fas-
teners to 54 N´m (40 ft. lbs.) using the following
sequence:
²The upper nut at the front of the compressor.
²The lower nut at the front of the compressor.
²The upper bolt at the rear of the compressor.
²The lower bolt at the rear of the compressor.
(12) On models with the 3.3L and 3.8L engines,
engage the retainer on the engine wire harness com-
pressor 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
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - 2.4L - INSTALLATION) or (Refer to 7 -
Fig. 6 Install Clutch Pulley
1 - PULLEY ASSEMBLY
2 - WOOD BLOCK
24 - 18 CONTROLS - FRONTRS
A/C COMPRESSOR CLUTCH/COIL (Continued)

COOLING/ACCESSORY DRIVE/DRIVE BELTS -
3.3L/3.8L - INSTALLATION).
(15) Lower the vehicle.
(16) Reconnect the battery negative cable.
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C-heater control to the A/C
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat
the opposing friction surfaces and provide a higher
compressor clutch torque capability.
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The compressor clutch relay (Fig. 7) 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 A/C compressor clutch relay is located in the
Integrated Power Module (IPM) in the engine com-
partment. See the fuse and relay layout map molded
into the inner surface of the IPM cover for A/C com-
pressor clutch relay identification and location.The black, molded plastic case is the most visible
component of the A/C compressor clutch relay. Five
male spade-type terminals extend from the bottom of
the base to connect the relay to the vehicle electrical
system, and the ISO designation for each terminal is
molded into the base adjacent to each terminal. The
ISO terminal designations are as follows:
²30 (Common Feed)- This terminal is con-
nected to the movable contact point of the relay.
²85 (Coil Ground)- This terminal is connected
to the ground feed side of the relay control coil.
²86 (Coil Battery)- This terminal is connected
to the battery feed side of the relay control coil.
²87 (Normally Open)- This terminal is con-
nected to the normally open fixed contact point of the
relay.
²87A (Normally Closed)- This terminal is con-
nected to the normally closed fixed contact point of
the relay.
OPERATION
The A/C compressor clutch relay is an electrome-
chanical switch that uses a low current input from
the powertrain control module (PCM) to control the
high current output to the compressor clutch electro-
magnetic coil. The movable common feed contact
point is held against the fixed normally closed con-
tact point by spring pressure. When the relay coil is
energized, an electromagnetic field is produced by the
coil windings. This electromagnetic field draws the
movable relay contact point away from the fixed nor-
mally closed contact point, and holds it against the
fixed normally open contact point. When the relay
coil is de-energized, spring pressure returns the mov-
able contact point back against the fixed normally
closed contact point. The resistor or diode is con-
nected in parallel with the relay coil in the relay, and
helps to dissipate voltage spikes and electromagnetic
interference that can be generated as the electromag-
netic field of the relay coil collapses.
The compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the integrated power module (IPM). The
inputs and outputs of the A/C 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.
Fig. 7 A/C Compressor Clutch Relay
RSCONTROLS - FRONT24-19
A/C COMPRESSOR CLUTCH/COIL (Continued)