Pontiac FIREBIRD 1972 Service Manual page 208

AUTOMATIC TEMPERATURE CONTROL
1 B-2 1
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TEST E
DOOR, ADJUST ARM O R REPLACE
N O VACUUM
YACUU.M. N O VACUIIC?_
FOR LEA. OR RESTRICTION lh BLACK HOSE BETWEEh PORT ,OF
cohTRoLI
VACJJMAT PORT OOF COhTROL PANEL VACJUM V A - V d
PANEL VACJUM VALVE A h D PORT I OF PROGRAMMER VACJUM VA-VE.
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VACUUM N O VACUUM
REPLACE CONTROL PANEL VACUUM
VALVE.
CH~CKEAK
OR RESTRICTION IN BLACK HOSE SUPPLYING ENGINE VACUUM.
TEST E,
(A) WITH ENGINE RUNNING AND AT OPERATING TEMPERATURE, SYSTEM IN NORMAL;
TEMPERATURE CONTROL AT MAXIMUM HEAT
,
BLOWER RANGE SWITCH O N HI,
(B) CHECK VACUUM CIRCUITRY TO DIVERTER DOORS. TAN AND TAN STRIPE HOSES SHOULD B E VENTED, PlNK AND PlNK STRIPE HOSES SHOULD HAVE VACUUM.
CHECK FOR LEAK OR RESTRICTION I N PlNK HOSE OR PINK STRIPE HOSE.
TEST E,
TEST Eg CONSISTS OF TEST E PLUS TEST E2.
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IF ABOVE CHECKS A R E OK, (HECK FOR SHORT I N SENSOR STRING, AND REPLACE OR REPAIR AS NEcEssmyJ
TEST F
(A) WlTH ENGINE RUNNING AT OPERATING TEMPERATURE,
(B) SYSTEM I N NORMAL, BLOWER RANGE SWITCH S E T TO HI TEMPERATURE CONTROL S E T TO MAXIMUM HEAT
(c) ROTATE TEMPERATURE CONTROL TO MAXIMUM A/C
.
OBSE'RVE MOVEMENT OF PROGRAMMER ASSY.
ARM.
I ~ S H O U L D EXTEND FURTHER OUT OF PROGRAMMER.
!
PROGWMER ARM M m
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v i
ARM&
~ ~ M O J E
CHECK FOR OPEh CIRCUIT
Ih
SENSOR STRING OR TEMPERATURE CONTROL.
INSERT OTHER PROBE INTO BLACK WlTH SINGLE WHITE STRIPE Wl R E AT HI-BLOWER RELAY.
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(D) HI-BLOWER RELAY SHOULD PICK UP
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r ' l
REPLACE HI-BLOWER RELAY.
(E) USING A I 2 VOLT TEST LAMP OR A VOLTMETER, WITH ONE PROBE TO GROUND
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rEsr LIGHT DOES NOT LIGHT
INSERT PROBE INTO BLACK WlTH SINGLE WHITE STRIPE WlRE AT BLOWER RANGE SWITCH.
SENSOR STRING OPEN REPAIR OR
TEST LlGHT LIGHTS
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REPLACE BLOWER RANGE SWITCH.
SENSOR STRING OK S E E
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TEST LIGHT LIGHTS
CHECK WIRING BETWEEN HI-BLOWER RELAY AND BLOWER RANGE SWITCH.
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TEST LlGHT DOES NOT LlGHT
INSERT PROBE INTO BLACK WlTH DOUBLE WHITE STRIPE WlRE AT PROGRAMMER.
REPLACE A S NECESSARY
TEST LIGHT DOES NOT LIGHT
INSERT PROBE INTO BLACK WITH DOUBLE WHITE STRIPE WIRE AT BLOWER RANGE SWITCH.
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TEST LIGHT DOES NOT L W
CHECK WIRING BETWEEN BLOWER RANGE SWITCH AND PROGRAMMER.
PROGRAMMER DIAGNOSIS.
TEST GI
(A)
WlTH ENGINE RUNNING AT OPERATING TEMPERATURE,
(B) SYSTEM I N NORMAL, BLOWER RANGE SWITCH S E T TO HI, TEMPERATURE CONTROL S E T TO MAXIMUM A/C
(C) OBSERVE A/C COMPRESSOR. IT SHOULD B E RUNNING.
(Dl USING A 12 VOLT TEST LAMP OR A VOLTMETER. WITH ONE PROBE TO GROUND
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COMPRESSOR RUNNING
CHECK AND REPAIR A/C SYSTEM A S NECESSARY.
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!EST-LLGHT_DOS h K L j G H I
CHECK COMPRESSOR CLlnCH GROUhD. IF DEFECTIVE, CORRECT. IF GOOD, REPAIR OR REPLACE CLUTCH AS h E C E l S A R ~ L E R T PROM INTO RED WIRE AT AMBIEhT SWITCH1
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T E S T LIGHT DOES k O T LIGdT
IGEK
iTRiKZLTiZFGKn~~~~
SWITCH AND MASTER
SWI T CH]
Fig. 18-1
8 ATC
Diagnosis Guide