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24 - 24
CONTROLS - REAR
BLOWER MOTOR RELAY (Continued)
DIAGNOSIS AND TESTING
The #1 and #2 rear blower motor relays (Fig. 2) are
located in the relay block of the rear evaporator
housing. Remove the rear blower motor relays from
the relay block to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75 ± 5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, refer to the appropriate wiring infor-
mation for circuit descriptions and diagrams. If not
OK, replace the faulty relay.
Fig. 2 Blower Motor Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the rear evaporator
housing.
(3) Refer to the relay block for blower motor relay
identification.
(4) Unplug the blower motor relay from the relay
block and remove it.
INSTALLATION
(1) Install the blower motor relay by aligning the
relay terminals with the cavities in the relay block
and pushing the relay firmly into place.
(2) Install the rear evaporator cover.
(3) Reconnect the battery negative cable.
CONTROL MODULE
DESCRIPTION
The rear A/C control module is mounted to the
upper left side of the rear evaporator housing in the
rear compartment, where it can be accessed for ser-
vice.
The rear A/C control module has wire connections
to the rear A/C blower motor switch, rear evaporative
temperature sensor, solenoid valve, rear A/C temper-
ature control and the temperature sensor. The rear
A/C control module cannot be repaired and, if faulty
or damaged, it must be replaced.
OPERATION
The rear A/C control module is supplied battery
power through the rear blower switch and a 7.5 amp
fuse. The control module receives input signals from
the rear A/C blower motor switch, rear A/C tempera-
ture control, rear temperature sensor and the rear
evaporator temperature sensor when the front A/C
switch is turned on. The rear A/C control module
uses the input signals to control rear blower motor
speed and output air temperature, and to prevent
freezing of the rear evaporator core.
DIAGNOSIS AND TESTING
For circuit descriptions and diagrams, refer to Air
Conditioning/Heater in Group 8W - Wiring Diagrams.
NOTE: Prior to checking rear A/C control module
circuits, verify that the front A/C system is operat-
ing properly.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear dome light from the rear roof
duct panel (Fig. 3).
(3) Disconnect the dome light wire harness connec-
tor and remove the dome light from vehicle.
(4) Remove the six push-pin roof duct panel fasten-
ers and remove the duct panel from the vehicle.
(5) Remove the five evaporator panel screws at the
front of the panel.
(6) If equipped, remove the interior motion sensor
from the evaporator panel, disconnect the wire har-
ness connector and remove the motion sensor from
the vehicle (Fig. 4).
(7) Remove the three push-in evaporator panel fas-
teners at the rear of the panel.
VA
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