OPERATION
The ISO-sta ndard rea r A/C clut ch relay is an elec-
tromech anical switch t hat uses a low curr ent input
from the rear A/C contr ol module to contr ol the h igh
curren t out put to the r ear A/C clutch. The mova ble,
common feed relay conta ct is held aga inst the fixed,
normally closed rela y contact by sprin g pressure.
When t he elect romagnetic relay coil is energized, it
dr aws th e movable com mon feed r elay con tact a way
from the fixed, norma lly closed relay con tact and,
holds it aga inst the fixed, nor mally open relay con-
tact. This action allows high cu rren t to flow to the
A/C clut ch field coil.
When the relay coil is de-en ergized, spring pres-
su re ret urns t he movable relay contact back a gainst
the fixed, n orma lly closed cont act point. The resistor
or diode is con nected in parallel with the relay coil,
and h elps to dissipate voltage spikes a nd electrom ag-
netic interfer ence th at can be gen erat ed as t he elec-
tromagnetic field of the r elay coil collapses.
The r ear A/C clutch relay ter mina ls are con nected
to the vehicle elect rical system t hrough a r eceptacle
in the r elay block located in the rear A/C evapora tor
housin g.
The r ear A/C clutch relay can not be repa ired an d,
if faulty or da maged, it must be replaced. Refer to
the appropr iate wiring inform ation for dia gnosis and
testing of the ISO-sta ndard relay a nd for complete
HVAC wiring diagrams.
REMOVAL
(1) Disconn ect and isolate the negat ive ba tter y
cable.
(2) Remove th e air filter from the rea r A/C evapo-
rator hou sing (Refer t o 24 - H EATING & AIR CON-
DITIONING/DISTRIBUTION - REAR/AIR F ILTER -
REMOVAL).
(3) Reach up int o the rear A/C evaporator hou sing
and r emove the rea r A/C clutch rela y 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
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