Pontiac FIREBIRD 1972 Service Manual page 242

AUTOMATIC TEMPERATURE CONTROL 1B-55
,
3. Remove hex screw, retaining clip and transducer.
4. To replace, reverse removal procedure. Refer to Figs.
1B-55 and 1B-56.
AMPLIFIER CIRCUIT BOARD
1. Remove vacuum valve.
2. Remove two programmer electrical connector retain-
ing screws and lift connector body from amplifier
terminals.
3. Remove amplifier heatsink retainer clip and insula-
tor.
4. Remove (2) amplifier retaining screws at amplifier
feedback pdtenti.~meter.
-
5. Disconnect two wires at transducer. Note which wire
connects to each terminal.
6. Remove amplifier circuit board.
7. To replace, reverse removal procedure and calibrate
feedback potentiometer. See Figs. 1B-56 and 1B-57.
VACUUM MOTOR
1. Remove vacuum valve retaining studs and lift
vacuum valve to remove drive arm from boss on
vacuum motor mechanism.
2. Remove retaining clip and power spring from motor
mechanism.
3. Disconnect vacuum hose from port on motor.
4. Remove (2) motor retaining screws and remove mo-
tor, lifting upward.
WWEW
SPRING
Fig. 7 8 - 5 8 Vacuum Motor and Power Spring
5. To replace, reverse removal procedure. See Figs. 1B-
57 and 1B-58.
BLOWER RESISTOR WIPER ARM ASSEMBLY OR
FEEDBACK POT ARM ASSEMBLY
1. Remove vacuum valve and spring.
2. Remove vacuum motor and power spring.
3. Lift blower resistor wiper arm and feedback pot arm
off of blower resistor circuit board. Take care to lo-
cate single ball bearing making certain it is located in
bearing cup on blower resistor circuit board.
4. Separate blower resistor wiper arm from feedback pot
arm. Be sure to locate (2) single ball bearings and
insure their location in bearing cups on wiper arm.
5. To replace, reverse removal procedure. Make sure
ball bearings are properly located in bearing cups. See
Figs. 1B-58 and 1B-59.
MIX DOOR OPERATII JG ARM
1. Remove vacuum valve.
INSULATOR -PROGRAMMER
ELECTRICAL CONNECTOR
h
BL
FEEDBACK
POT ARM
ELECTRICeL
CONNECTOR RESISTOR
CIRCUIT
CUP
BOARD
I
I
Fig. 1 B-57 Amplifier Circuit Board Fig. 7 8 - 5 9 Blower Wiper Arm and Feedback Pot Arm