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, 2.5L and 2.8L
engines, loosely install the four bolts that secure the
A/C compressor to the mounting bracket on the
engine (2.4L), or the cylinder block (2.5L/2.8L).
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 A/C compressor to the engine. Tighten each of the
fasteners to 54 N·m (40 ft. lbs.) using the following
sequence:
• The upper nut at the front of the compressor.
• The lower nut at the front of the compressor.
• The upper bolt at the rear of the compressor.
• The 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 A/C compressor.
(13) Connect the engine wire harness connector to
the A/C compressor clutch coil.
(14) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
INSTALLATION).
(15) Lower the vehicle.
(16) 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 integrated
power module (IPM) in the engine compartment.
OPERATION
The ISO-standard A/C clutch micro-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 electro-
magnetic relay coil is energized, it draws the mov-
able 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 integrated power module (IPM). The inputs and
outputs of the A/C compressor clutch relay include:
• The common feed terminal (30) receives a bat-
tery current input from a fuse in the IPM through a
fused B(+) circuit at all times.
• The 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.
• The coil battery terminal (86) receives a battery
current input from the PCM through a fused ignition
Fig. 8 A/C Compressor Clutch Relay
CS
CONTROLS - FRONT
24 - 17
A/C COMPRESSOR CLUTCH/COIL (Continued)