Component Tests and General Diagnostics

SYSTEM DIAGNOSIS AND TESTING

Fig. 2 Wiper/Washer System Wiring:

Refer to wiring diagrams, Figs. 2 and 3, during diagnosis and testing procedures.


WIPER DIAGNOSIS
1. If wiper motor does not run, check lead and coupler connections. If satisfactory, check the following:
a. Blown or incorrectly mounted fuse.

Fig. 4 Wiper/Washer Switch Continuity:

b. Check wiper switch by disconnecting couplers and checking continuity between terminals as shown, Fig. 4, using a circuit tester.
c. Check for a break in wiper motor armature or poor commutator brush contact by measuring continuity between blue lead and ground, and blue/red wire and ground.

NO-LOAD RUN TEST
1. Perform low-speed test as follows:
a. Connect battery positive terminal to blue terminal on motor and battery negative terminal to motor case.
b. If motor rotates at 45-57 RPM, motor is operating properly.
c. If not, motor is defective, replace motor.
2. Perform high-speed test as follows:
a. Connect battery positive terminal to blue/red terminal on motor and battery negative terminal to motor case.
b. If motor rotates at 67-81 RPM, motor is operating properly.
c. If not, motor is defective, replace motor.


AUTOMATIC STOP ACTION TEST
1. Connect battery positive terminal to yellow terminal of motor and battery negative terminal to motor case, then connect a jumper between blue/white and blue/black terminals of motor.
2. Motor output shaft should come to a halt at a certain angular position, corresponding to starting position of wiper blade.
3. Stop motor a number of times, and ensure motor stops in same position each time.

INTERNAL WIPER RELAY TEST
1. Disconnect wiper and washer switch electrical connector, then turn wiper switch to INT position.
2. Connect battery positive terminal to yellow/white terminal and battery negative terminal to black terminal.
3. If an operating sound is emitted, relay is operating properly.