Pontiac Fiero 1988 Service Manual page 32

HEATING AND VENTILATION 1A-7
2 > BLOWER ELECTRICAL
B L O W E R MOTOR INOPER-
ATIVE AT ANY S P E E D
BLOWER MOTOR INOPERATIVE ONLY
AT CERTAIN S P E E D S
C H E C K F U S E IN F U S E
PANEL
r
I
F U S E BLOWN
F U S E OK
WITH T H E IGNITION
SWITCH ON & T H E
B L O W E R ON HIGH, U S E A
S H O R T D E T E C T O R TO
LOCATE S H O R T IN T H E
FOLLOWING W I R E S :
1. F R O M T H E F U S E PANEL
TO T H E B L O W E R S P E E D
SWITCH.
2. F R O M T H E B L O W E R
S P E E D S W I T C H TO T H E
HEATER R E S I S T O R B L O C K .
3. FROM T H E HEATER R E -
SISTOR B L O C K
TO B L O W E R MOTOR.
D I S C O N N E C T R E S I S T O R B L O C K CON-
NECTOR, C O N N E C T ONE LEAD O F A
S E L F P O W E R E D T E S T LIGHT TO ANY
ONE LEAD ON T H E R E S I S T O R B L O C K
AND U S E T H E O T H E R LEAD TO P R O B E
EACH O F T H E O T H E R TWO TERMINALS.
WITH T H E IGNITION
SWITCH ON & T H E
BLOWER ON HIGH,
C H E C K T H E BLOWER
MOTOR GROUND.
T E S T LIGHT
D O E S NOT
LIGHT ON
ALL
TERMINALS
POOR OR
NO
GROUND
GROUND
OK
REPAIR
GROUND
T E S T LIGHT
LIGHTS ON
ALL
TERMINALS
R E P L A C E
R E S I S T O R
C H E C K MOTOR
C O N N E C T O R
WITH A 12 VOLT
T E S T LIGHT
T E S T LAMP D O E S
NOT LIGHT
T E S T LAMP LIGHTS
U S E T H E 12 VOLT
T E S T LIGHT TO
C H E C K T H E POWER
F E E D TERMINAL ON
T H E B L O W E R
S P E E D SWITCH
R E P A I R O P E N IN F E E D
WIRE FROM R E S I S T O R TO
BLOWER MOTOR.
WITH IGNITION OFF, DISCON-
N E C T C O N N E C T O R FROM R E -
SISTOR BLOCK. C O N N E C T A
JUMPER LEAD FROM T H E BAT-
T E R Y POSITIVE TERMINAL TO
ANY WIRE TERMINAL IN T H E
CONNECTOR. U S E 12 VOLT
T E S T LIGHT TO C H E C K F O R
VOLTAGE AT T H E C O R R E S -
PONDING WIRE ON T H E
BLOWER S P E E D SWITCH.
REPEAT T H E SAME T E S T
ON O T H E R W I R E S .
T E S T LAMP D O E S
LIGHT
T E S T LAMP LIGHTS LAMP LIGHTS
ON ALL
T H R E E W I R E S
LAMP D O E S NOT
LIGHT ON ALL
T H R E E W I R E S
REPAIR O P E N IN POWER
WIRE FROM BLOWER
S P E E D SWITCH
TO F U S E PANEL
R E P L A C E
SWITCH
R E P L A C E
BLOWER S P E E D
SWITCH
REPAIR O P E N IN
A F F E C T E D WIRE
" 2 0 0 0 5 1 A
Figure 8 Blower Electrical Diagnosis