Diagnosis Of Windshield Wiper - P-Models; Wiper System Checks - GMC G Service Manual

8A-34 CAB ELECTRICAL
LINKAGE CONNECTED
WIPER GEAR IS STRIPPED.
REPLACE THE WIPER MOTOR.
DIAGNOSIS OF WINDSHIELD WIPER — P-MODELS

WIPER SYSTEM CHECKS

1. Inspect for the following items:
a. Wiring harness is securely connected to wiper
switch.
b. Wiper motor is securely grounded to body.
c. Wiper switch is securely mounted and
grounded.
d. Check fuse.
2. If items in Step 1 check out, try operating wiper in
both LO and HI speeds, then turn wiper "off" (blades
should return to park position). If wiper fails to operate
correctly, proceed to Step 3.
3. Disconnect wiring harness from wiper and try operat­
ing wiper as shown in figures 38, 39, and 40.
4. If wiper operates correctly independently of switch
and vehicle wiring, refer to "DIAGNOSIS OF WIPER
— ON VEHICLE."
5. If wiper still fails to operate correctly in Step 3, discon­
nect wiper linkage from motor crank arm and try oper­
ating wiper again. If wiper operates correctly
independently of linkage, check linkage for cause of
malfunction.
6. If wiper fails to operate correctly independently of link­
age (Step 4), remove wiper motor from vehicle and
refer to "DIAGNOSIS OF WIPER — OFF VEHICLE."
PROCEDURE 8 (WIPER RUNS BUT BLADES DON'T MOVE)
CHECK THE WIPER LINKAGE CONNECTION TO THE WIPER CRANK ARM
Figure 37 — Wiper Diagnosis
LINKAGE DISCONNECTED
CHECK THE LINKAGE AND
CHECK THE SYSTEM.
30. Terminal No. 2
31. Terminal No. 1
32. Terminal No. 3
33. Ammeter; 0-30 Ampere Range
34. Gear Shaft In The Park Position
35. Wiper Ground Strap
Figure 38 — Jumper Connections — Low Speed
F-00745
F-00808