OPERATION
The ISO-standard rear A/C clutch relay is an elec-
tromechanical switch that uses a low current input
from the rear A/C control module to control the high
current output to the rear A/C clutch. 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 con-
tact. 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 rear A/C clutch relay terminals are connected
to the vehicle electrical system through a receptacle
in the relay block located in the rear A/C evaporator
housing.
The rear 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 relay and for complete
HVAC wiring diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the air filter from the rear A/C evapo-
rator housing (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION - REAR/AIR FILTER -
REMOVAL).
(3) Reach up into the rear A/C evaporator housing
and remove the rear A/C clutch relay from the relay
block (Fig. 2).
Fig. 1 Rear A/C Clutch Relay
1 - STANDARD ISO RELAY
2 - TERMINAL PATTERN
VA
CONTROLS - REAR
24 - 25