3-24. ACCESSORIES TROUBLESHOOTING (CONT)
TEST OR INSPECTION
2. WINDSHIELD WIPER MOTOR DOES NOT OPERATE (Cont).
S t e p 4 . ( C o n t ).
b. If multimeter indicates 24 volts, a short circuit to ground
e x i s t s i n c a b e l e c t r i c a l c i r c u i t . I s o l a t e d e f e c t i v e c i r c u i t b y
reconnecting wire from cab relay BAT. terminal to long, silver
terminal of cab circuit breaker. Then, at cab switch panel, dis-
connect and tape wires connected to each of the three circuit
breakers one at a time and check if remaining circuit(s) operate
when associated switch is operated. If circuit is okay, problem
is in circuit associated with breaker from which wire was dis-
Press 3 ampere circuit breaker on cab switch panel.
Check if windshield wiper operates.
a. If windshield wiper operates, problem was momentary short in
c i r c u i t . I f c i r c u i t b r e a k e r b l o w s , a s h o r t t o g r o u n d e x i s t s in
circuit. Isolate by checking wiring for worn insulation. If
wiring okay, perform resistance check of wiper motor. Replace
parts as necessary (page 10-13).
b. If windshield wiper does not operate, go to step 6 below.
Step 6. Turn ignition key switch to off
p o s i t i o n.
Remove HEAT CONTROL knob from
cab switch panel by pulling
s t r a i g h t u p o f f c o n t r o l s h a f t .
Remove four screws securing cab
Carefully pull cab switch panel
upwards from heater console just
enough to gain access to FRONT
WIPER switch terminals.
Connect multimeter between FRONT
WIPER switch B terminal and
c h a s s i s .
Turn ignition key switch to on
p o s i t i o n.
Multimeter shall indicate 24 volts.
a. If 24 volts not obtained, replace 3 ampere circuit breaker (page