Initial Inspection and Diagnostic Overview

Fig. 21 Typical rear window wiper motor:

Fig. 22 Typical rear wiper wiring diagram:

CHEVETTE & 1000; CAVALIER, CIMARRON, FIRENZA, 2000 & SKYHAWK; CAMARO & FIREBIRD
The rear wiper system consists of a one speed motor and drive gear enclosed in a metal housing. The motor is protected by an internal automatic reset circuit breaker. There are four terminals on the motor and gearbox assembly. Terminals 1 and 2 are located on the park switch and control the park function. Terminals 3 and 4 are the motor run terminals, Fig. 21. Rotating the wiper switch to the on position provides battery voltage to motor terminal 3. The circuit is completed to ground through terminal 4, Fig. 22. When the control switch is turned off, current is supplied to terminal 3 through the park switch. The wiper will continue to run until the park switch is opened by a cam located in the wiper motor transmission housing.



DIAGNOSIS
Switch
1. Turn ignition switch and wiper switch on and check both output terminals on the wiper switch for current using test lamp.
2. If lamp does not light at either terminal, check for blown fuse or open circuit in power feed circuit. If current is present at only one terminal, switch is defective. With ignition on and control switch in off position, park switch gray wire should have current present and motor run terminal white wire should have no current present.
Motor
1. With ignition and wiper control switch in on position, check for current at motor terminal 3 using test lamp. If lamp does not light, check for open circuit in white wire or faulty control switch. If lamp lights but motor does not operate, check continuity between motor terminal 4 and ground.
2. If current is present at terminal 3 and motor ground circuit is satisfactory, repair or replace motor as necessary.
Park Switch
1. Turn ignition on and control switch off.
2. Check for current at motor terminal 1 using suitable test lamp.
3. If lamp does not light, check for open circuit in gray wire or faulty control switch.
4. If lamp lights, connect jumper wire between motor terminals 1 and 2. If motor parks and stops, replace park switch. If motor does not park, repair wiring between terminals 1 and 2.