Dodge Neon / Neon SRT-4. Manual — part 426

(9) Remove the screw that secures the clutch coil

pigtail wire connector bracket and ground clip to the
top of the compressor housing.

(10) 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. 6).

INSTALLATION

(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. 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.

Fig. 4 Clutch Plate and Shim(s)

1 - A/C COMPRESSOR SHAFT
2 - CLUTCH PLATE
3 - SHIM

Fig. 5 Clutch Pulley Snap Ring

1 - SNAP RING
2 - SNAP RING PLIERS
3 - CLUTCH PULLEY AND BEARING

Fig. 6 Clutch Coil Snap Ring

1 - SNAP RING PLIERS
2 - CLUTCH FIELD COIL
3 - A/C COMPRESSOR
4 - SNAP RING

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A/C COMPRESSOR CLUTCH COIL (Continued)

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. 7).

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 2.54 mm (0.010 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 - 0.66 mm (0.014 - 0.026
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) Install the bolts that secure the A/C compres-

sor to the engine. Tighten the bolts to 23 N·m (17 ft.
lbs.).

(11) Connect the engine wire harness connector to

the A/C compressor clutch coil.

(12) Install the accessory drive belt (Refer to 7 -

COOLING/ACCESSORY

DRIVE/DRIVE

BELTS

-

INSTALLATION).

(13) Lower the vehicle.
(14) Reconnect the negative battery cable.

A/C COMPRESSOR CLUTCH
RELAY

DESCRIPTION

The A/C clutch relay (Fig. 8) is a International

Standards Organization (ISO) micro-relay. Relays
conforming to the ISO specifications have common
physical dimensions, current capacities, terminal
functions and patterns. The ISO micro-relay terminal
functions are the same as a conventional ISO relay.
However, the ISO micro-relay terminal pattern (or
footprint) is different, the current capacity is lower,
and the physical dimensions are smaller than those
of the conventional ISO relay.

The A/C clutch relay is located in the power distri-

bution center (PDC) in the engine compartment.

Fig. 7 Clutch Pulley - Installation

1 - PULLEY AND BEARING
2 - WOOD BLOCK

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24 - 13

A/C COMPRESSOR CLUTCH COIL (Continued)

TERMINAL LEGEND

NUMBER

IDENTIFICATION

30

COMMON FEED

85

COIL GROUND

86

COIL BATTERY

87

NORMALLY OPEN

87A

NORMALLY CLOSED

OPERATION

The A/C clutch relay is an electromechanical

switch that uses a low current input controlled by
the powertrain control module (PCM) to control the
high current output to the A/C clutch field coil. The
movable, common feed relay contact is held against
the fixed, normally closed relay contact by spring
pressure. When the electromagnetic relay coil is
energized, it draws the movable common feed relay
contact away from the fixed, normally closed relay
contact and, holds it against the fixed, normally open
relay contact. This action allows high current to flow
to the A/C clutch field coil.

When the relay coil is de-energized, spring pres-

sure returns the movable relay contact back against
the fixed, normally closed contact point. The resistor
or diode is connected in parallel with the relay coil,
and helps to dissipate voltage spikes and electromag-
netic interference that can be generated as the elec-
tromagnetic field of the relay coil collapses.

The A/C clutch relay terminals are connected to

the vehicle electrical system through a receptacle in
the power distribution center (PDC). The inputs and
outputs of the A/C clutch relay include:

• The common feed terminal (30) receives a bat-

tery current input from a fuse in the PDC through a
fused B(+) circuit at all times.

• The coil ground terminal (85) receives a ground

input from the PCM through the A/C clutch relay
control circuit only when the PCM electronically
pulls the control circuit to ground.

• The coil battery terminal (86) receives a battery

current input from a fuse in the fuse block module
through a fused ignition switch output (run-start) cir-
cuit only when the ignition switch is in the On or
Start positions.

• The normally open terminal (87) provides a bat-

tery current output to the compressor clutch coil
through the A/C clutch relay output circuit only when
the A/C compressor clutch relay coil is energized.

• The normally closed terminal (87A) is not con-

nected to any circuit in this application, but provides
a battery current output only when the A/C clutch
relay coil is de-energized.

The A/C clutch relay cannot be repaired and, if

faulty or damaged, it must be replaced. Refer to the
appropriate wiring information for diagnosis and
testing of the ISO-standard micro-relay and for com-
plete HVAC wiring diagrams.

REMOVAL

(1) Disconnect and isolate the negative battery

cable.

(2) Open the cover of the power distribution center

(PDC) located in the engine compartment (Fig. 9).

NOTE: Refer to the fuse and relay layout map on
the inside of the PDC cover for A/C clutch relay
location.

(3) Remove the A/C clutch relay from the PDC.

INSTALLATION

NOTE: Refer to the fuse and relay layout map on
the inside of the power distribution center (PDC)
cover for A/C clutch relay location.

(1) Position the A/C clutch relay into the receptacle

of the PDC.

(2) Align the A/C clutch relay terminals with the

terminal cavities in the PDC receptacle and push
down firmly on the relay until the terminals are fully
seated.

(3) Close the cover of the PDC.
(4) Reconnect the negative battery cable.

Fig. 8 A/C Clutch Relay

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A/C COMPRESSOR CLUTCH RELAY (Continued)

A/C HEATER CONTROL

DESCRIPTION

Both the heater-only and heater-A/C systems use a

combination of, electrical, cable, and vacuum con-
trols. These controls provide the vehicle operator
with a number of setting options to help control the
climate and comfort within the vehicle.

The A/C-heater control for the heater-only or the

heater-A/C system is located to the right of the
instrument cluster in the instrument panel. The A/C-
heater control contains rotary-type knobs. There is a
blower motor speed switch, mode control switch, tem-
perature control, and airflow control.

The A/C-heater control cannot be repaired and, if

faulty or damaged, it must be replaced. The control

knobs and the illumination lamps are available for
service replacement.

DIAGNOSIS AND TESTING

VACUUM CONTROL SYSTEM

Use an adjustable Vacuum Test Set (Special Tool

C-3707-B or equivalent) and a suitable vacuum pump
to test the heater-A/C vacuum control system. With a
finger placed over the end of the Vacuum Test Probe
(Fig. 10), adjust the bleed valve on the Vacuum Test
Gauge to obtain a vacuum of exactly 27 kPa (8 in.
Hg.). Release and block the end of the Vacuum Test
Probe several times to verify that the vacuum read-
ing returns to the exact 27 kPa (8 in. Hg.) setting.
Otherwise, a false reading will be obtained during
testing.

HEATER-A/C VACUUM SYSTEM DIAGNOSIS

Condition

Possible Causes

Correction

No Forced Air in Heat
Position

1. Vacuum line pinched or
leaking.

1. Locate and repair vacuum leak or pinched line.

2. Faulty heat defroster or
mode door.

2. Test actuators and door operation. Repair as
necessary.

3. Faulty selector switch.

3. Test selector switch and replace if necessary.

4. Vacuum check valve.

4. Test check valve and replace if necessary.

Fig. 9 Power Distribution Center - LHD Shown, RHD

Typical

1 - PDC

Fig. 10 Adjust Vacuum Test Bleed Valve

1 - VACUUM PUMP TOOL C-4289
2 - VACUUM TEST SET C-3707
3 - BLEED VALVE
4 - PROBE

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A/C HEATER CONTROL (Continued)