Pontiac FIREBIRD 1972 Service Manual page 206

AUTOMATIC TEMPERATURE CONTROL
1B-19
AUTOMATIC TEMPERATURE CONTROL DIAGNOSIS GUIDE
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AIR CONDITIONING AUTOMATIC TEMPERATURE CONTROL FUNCTIONAL TEST
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1 . b )
START ENGINE A N D ALLOW TO RUN FOR 5 MINUTES, OR UNTIL SYSTEM IS STABILIZED BEFORE PROCEEDING.
(8) SYSTEM OFF, SET BLOWER RANGE SWITCH TO HI. SET TEMPERATURE CONTROL TO MAXIMUM HEAT
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N O AIR FLOW FROM A N Y OUTLET
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PROGRAMMER RETURNS TO PARK POSITION
PROGRAMMER DOES N O T RETUlN TO PARK
AIR INLET DOOR NOT CLOSED!
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11. SYSTEM I N NORMAL
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(A) BLOWER OPERATES O N HlGH SPEED (MAYBE O N L Y MOMENTARILY).
(8) HOT AIR COMES M A I N L Y FROM HEATER OUTLET WITH SOME AIR FROM DEFROSTER OUTLETS.
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\BLOWER WILL NOT
OPERATE^
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~ O T AIR COMES F;OM A/C OUTLETSI
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C O O L AIR COMES
OM
A/C OUTLETS]
PERFORM TEST El
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PERFORM TEST E2
r " l
1111.
SET BLOWER RANGE SWITCH TO LO RANGE
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BLOWER SPEED A N D AIR FLOW DOES NOT DECREASE
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BLOWER SPEED AND AIR FLOW DECREASE
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REPLACE BLOWER RANGE SWITCH]
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I V . SYSTEM IV DEFROST
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AIR INLET DOOR DOES N O T G O TO FULL
OUTSIDE AIR POSITION.
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V. SYSTEM I N N O R W L SET TEMPERATME
CONTROL TO 75".
ALLOW
SYSTEM TO STABLIZE
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V I . (A) RETURN BLOWER RANGE SWITCH TO HI
(8) SET TEMPERATURE CONTROL TO MAXIMUM A/C
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BLOWER SPEED DOES N O T
G O FROM HI-LO-HI
PERFORM TEST F
SYSTEM DOES NOT G O I N T O 81-LEVEL OPERATlOh
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NORMAL AIR COMES M A I N L Y FROM DEFROSTER OUTLETS,
WlTH SOME AIR FROM HEATER OUTLET.
(
SYSTEM GOES l h T O 81-LEVEL OPERATlOh
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V I I I .
SYSTEM I N INSIDE
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AIR INLET DOOR MOVES TO INSIDE POSITION.
AIR INLET
DOOR
DOES NOT MOVE
TO INSIDE
POSITION.]
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TEST A
(A) WlTH ENGINE R U N N I N G AT OPERATING TEMPERATURE,
(8) SYSTEM OFF
,
BLOWER RANGE SWITCH SET TO HI, TEMPERATURE CONTROL SET TO MAXIMUM HEAT.
(C) USING A 12 VOLT TEST LAMP OR A VOLTMETER, WlTH ONE ROBE TO GROUND
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INSERT OTHER PROBE INTO RED WIRE ON CONTROL PANEL MASTER SWITCH.[
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TEST LIGHT LIGHTS
REPLACE DEFECTIVE MASTER SWITCH
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TEST LIGHT LIGHTS
REPLACE DEFECTIVE MASTER RELAY.
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TEST LIGHT DOES h O T LIGHT
SYSTEM IS INCORRECTLY WIRED. MASTER SWITCH A h D
ARE BY-PASSED. TRACE WIRING CIRCUIT TO BLOWER MOTOR A h D
Fig. 18-1 6 ATC Diagnosis Guide