TM 5-3805-262-20
3-24. ACCESSORIES TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
9. BOTH REAR DEFOGGER FANS DO NOT OPERATE (Cont).
S t e p 7 . ( C o n t ).
Turn ignition key switch to on position.
Check if 6 ampere circuit breaker blows.
a .
b .
If 6 ampere circuit breaker blows, short circuit exists in de-
f r o s t e r s w i t c h , r e s i s t o r , o r d e f r o s t e r m o t o r . P e r f o r m r e s i s t a n ce
check of these parts; replace defective part (page 10-52 or
10-58).
If 6 ampere circuit breaker button does not blow, short circuit
exists in wire disconnected from circuit breaker; repair or re-
place wire as necessary.
10. A REAR DEFOGGER FAN DOES NOT OPERATE.
Remove defogger fan that is not operating (page 10-62).
Remove switch from defogger fan (page 10-63).
Check switch for continuity in two end positions and open circuit in center
p o s i t i o n.
a .
b .
11. CAB DOME LIGHT
Replace switch if open circuit indicated in one or both end
p o s i t i o n s o r i f c o n t i n u i t y i n d i c a t e d i n c e n t e r p o s i t i o n .
Replace defogger fan motor if continuity obtained in both end
positions and open circuit obtained in center position.
DOES NOT OPERATE.
Step 1.
Ensure that ignition key switch is turned to on position.
Ensure that main and auxiliary switches on vehicle lights switch on
right instrument panel are in any position other than OFF.
Rotate DIMMER CMPT LIGHTS control completely clockwise.
Check if instrument panel cluster lamps are on.
a. If instrument panel cluster lamps are not on, go to page 3-71,
MALFUNCTION 1.
b. If instrument panel cluster lamps are on, go to step 2 below.
Step 2.
Replace cab dome light bulb (page 10-67).
Check that cab dome light operates.
a. If cab dome light operates, problem was burned out bulb.
b. If cab dome light does not operate, replace switch (page 10-68).
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