Chevrolet 1977 light duty truck, Service Manual

Page: 825 / 861

D I A G N O S I S - WIPER OFF VEHICLE
C O N D I T I O N A P P A R E N T C A U S E C O R R E C T I O N
1. W ip e r I n o p e ra tiv e o r
I n t e r m i t t e n t
A. B roken o r d a m a g e d g ear
train (only if inoperative) A. R eplace g ears as req u ired
B. P o o r solder co n n e c tio n s at
te rm in a l board
B. R e so ld e r wires at te rm in a ls
C. Loose splice jo in ts at b ru sh
plate C. R e c r im p o r s o ld e r splice
jo in ts
D. B rushes binding in b ru s h
h o ld e r
D. C lean h o ld e r o r replace
b ru s h , s p rin g o r b ru sh
p la te assem bly.
E. O p en circuit in a r m a t u r e E. R e p la c e a r m a t u r e
2. W ip e r will not shut-off:
A. W ip e r has n o r m a l "H i"
a n d " L o " speed A. Defective p a rk switch A. R e p la c e te rm in a l b o a rd
assem bly
B. G r o u n d e d red lead wire B. R e p a i r s h o rt circuit in
red wire
B. W ip e r h as " L o " speed only A. G r o u n d e d s h u n t field coil A. R e p la c e fra m e an d field
assem b ly
B. G r o u n d e d black wire
B. R e p a ir sh o rt circuit in
b la c k wire
C. W ip e r has " H i" sp eed only A. O p e n circuit in s h u n t field
coil
A. R e p la c e fra m e and field
a ssem b ly
B. O p e n circuit in black wire
B. R e p a ir b ro k e n wire o r p o o r
so ld e r co n n e c tio n
3. W ip e r sh u ts o ff - b u t
not in p a r k position
A. P a rk sw itch defective o r
c o n ta c ts dirty
A. R e p la c e te rm in a l b oard
assem b ly o r clean c o n ta c ts
4. " H i" speed to o fast A. R e sisto r defective
A. R e p la c e te rm in a l b o a rd
assem b ly