Contents Section: Wiper/washer Systems All sections

Wiper/washer System - Except "s" Series GMC Cab & Chassis R2500

Wiper/washer Systems 16 illustrations ~386 words

DESCRIPTION & OPERATION

Wiper system consists of a 2-speed permanent magnet-type motor. Wiper motor consists of field magnets, and armature and drive gear within upper and lower housings. The washer motor is assembled on bottom of washer fluid reservoir. (Scheme 1) Wiper motor is protected by an automatic reset circuit breaker. Vehicle wiring is protected by fuse in fuse block.

Washer motor is controlled by a washer switch, located on turn signal and multi-functional lever. Two wires go to washer motor. White wire has power from fuse box. Pink wire is the ground circuit that goes through washer switch to ground.

Scheme 1

Scheme 1: DESCRIPTION & OPERATION

* PLEASE READ FIRST *

Before proceding to any Diagnostic Procedures the following must be checked

  1. Continuity of all wires
  2. Wiper motor-to-dash mounting screws tight
  3. Fuses
  4. Washer hoses clear

Scheme 2

Scheme 2: WIPER WASHER SWITCH CIRCUIT DIAGRAMS

Scheme 3

Scheme 3

WIPER MOTOR

  1. If wiper motor functions in all modes (Scheme 4)or (Scheme 5).
  2. If motor does not function in any of checks see DIAGNOSIS CHART.

WASHER PUMP

  1. If motor does not run or pump water, replace washer pump.
  2. If motor runs and pumps water, problem is in circuit board, motor park switch or wiper switch. (Scheme 4)or (Scheme 5)

WIPER-WASHER SWITCH

Disconnect wiring harness from wiper motor and perform switch test in either (Scheme 4) or (Scheme 5) using a digital voltmeter and with the ignition switch on.

Scheme 4

Scheme 4: WIPER-WASHER SWITCH

Scheme 5

Scheme 5

DIAGNOSIS PROCEDURES CHART

SymptomProcedure
Pump Inoperative - Wiper Motor Operates1
Washer Pumps Continuously2
Wiper Motor Inoperative (All Modes)3
Lo Speed Only - Inoperative Hi4
Hi Speed Only - Inoperative Lo5
One Speed Only - Runs The Same In Both Speeds6
Wiper Shuts Off But Blades Don't Park7
Wiper Will Not Shut Off8
Intermittent Inoperative9
Wiper Motor Runs But Blades Don't Move10
Wiper Parks Above Park Position11

DIAGNOSIS CHART

Scheme 6

Scheme 6: PROCEDURE 1

Scheme 7

Scheme 7: PROCEDURE 2

Scheme 8

Scheme 8: PROCEDURE 3

Scheme 9

Scheme 9: PROCEDURE 4

Scheme 10

Scheme 10: PROCEDURE 5

Scheme 11

Scheme 11: PROCEDURE 6

Scheme 12

Scheme 12: PROCEDURE 7

Scheme 13

Scheme 13: PROCEDURE 8

Scheme 14

Scheme 14: PROCEDURE 9

Scheme 15

Scheme 15: PROCEDURE 10

Scheme 16

Scheme 16: PROCEDURE 11

Removal ("C" & "K" Series)

  1. Ensure wiper motor is in park position and negative battery cable is disconnected. Disconnect electrical harness at motor. Disconnect hoses at washer pump. Reach through access hole in cowl grille and loosen wiper drive rod attaching screws.
  2. Remove drive rod from wiper motor crank arm. Remove screws attaching wiper motor to instrument panel and remove motor assembly.

Installation ("C" & "K" Series)

To install, reverse removal procedure. Lubricate crank arm pivot prior to installation.

OVERHAUL

Repairs to motor/gear box section of wiper assembly are limited to switch, armature, cap and brush holder assembly, plus external parts, crankarm, spacer and seal (plastic) and output shaft seal.

WIRING DIAGRAMS

For wiring diagrams, refer to appropriate chassis wiring diagram in WIRING DIAGRAMS section.