Pontiac Fiero 1988 Service Manual page 1270

MISCELLANEOUS ACCESSORIES 9F-3
CONDITION
CAUSE
CORRECTION
System is
inoperative
(monitor lamp
will
not light)
Circuit breaker open
from an electrical short
in the power feed circuit
Check for electrical short in power feed circuit of
body harness. Circuit breaker will reset itself when
short circuit is corrected.
Burned fusible
link
Check for short circuit between starter solenoid
and circuit breaker.
Burned out or missing
monitor lamp
Check lamp mounted in switch.
Open circuit in either
of the wiring harnesses
Check affected wiring for open circuit and check
wiring connectors.
Inoperative or dis-
connected control
Check harness connection to timer assembly.
timer assembly
Check for proper ground.
Check for relay "pull in" (click) when 12 volts is
applied to the light blue wire terminal of timer
assembly. If no pull in, replace timer assembly.
Defective control
switch
With switch held in "ON" position and connector
installed on switch, connect a test light to the
light blue wire terminal with connector on rear
of switch to ground. Test light should glow
brightly; if not, replace switch.
System operates but
will not turn off auto-
matically in 10-15
minutes
Defective
control
switch
With test light connected to center terminal as
described in step above, test light should glow
brightly in "ON" position and dim when switch is
released. If not, switch is defective.
Defective control
timer assembly
Replace timer assembly.
System operates but
won't stay on for full
time
cycle
Defective control
timer assembly
Replace timer assembly.
520228-9
Fig. 3 Electric Rear W i n d o w Defogger Diagnosis