Wiper and Washer Systems: Testing and Inspection

Fig. 5 Compound Wound Round Windshield Wiper Motor W/multiplex Pulse System:

WIPERS INOPERATIVE

1. Turn ignition on and, with wiper switch off, ground 12 volt test lamp and touch probe to wiper terminal No. 2, Fig. 5.
2. If lamp fails to light, proceed as follows:
a. Check wiper system fuse and replace if needed.
b. If fuse blows again, check for short in wire to terminal Nos. 2 and 5, or the motor for high amperage draw.
c. If fuse is satisfactory, repair open in feed circuit between fuse block and wiper motor.
3. If lamp lights in step 1, touch probe to wiper terminal No. 1.
4. If wipers run, check for open circuit in wire between terminal No. 1 and wiper switch and, if wire is satisfactory, check wiper switch.
5. If wipers do not run, Place wiper switch in LO position and touch probe to terminal No. 6.
6. If wipers run, check for open circuit in wire between terminal No. 6 and wiper switch and, if wire is satisfactory, check wiper switch.
7. If wipers do not run, remove washer pump cover and reattach wiring to wiper.
8. With wiper in LO position, ground 12 volt test lamp and touch probe to terminal of red wire at pulse relay.
9. If lamp does not illuminate, proceed as follows:
a. Check connection to No. 1 wiper terminal.
b. Check for open in red wire.
c. Replace park relay.
10. If lamp illuminates, touch probe to terminal of orange wire at pulse relay.
11. If wipers run, replace timing circuit board assembly.
12. If wipers do not run, touch probe to terminal of pink/black stripe wire at pulse relay.
13. If lamp illuminates, repair wiper motor.
14. If lamp does not illuminate, replace pulse relay.

WIPERS WILL NOT SHUTOFF, BLADES OPERATE IN NORMAL WIPE PATTERN

Fig. 18 Gearbox Relay & Drive Gear Assembly Inspection:

Fig. 21 Ratchet Wheel And Override Switch Assembly:

1. Operate wipers with switch in delay position.
2. If wipers operate properly in delay position, proceed as follows:
a. Place wiper switch in off position, disconnect electrical connector to gearbox relay, and connect test lamp between terminals 1 and 2 in connector, Fig. 5.
b. If lamp lights, check for grounded wire between motor and switch or defective switch, and repair as needed.
c. If lamp does not light, remove washer pump and inspect park relay spring, Fig. 18. If spring is properly installed, replace park relay.
3. If wipers do not operate properly in delay position, proceed as follows:
a. Place wiper switch in off position, then turn ignition off and on.
b. If wipers park properly, check condition and adjustment of holding switch, and repair as needed.
c. If holding switch is satisfactory, replace pulse timer assembly.
d. If wipers do not shutoff, inspect override switch contacts, Fig. 21.
e. If switch contacts are held open by ratchet wheel, check for grounded blue wire and repair as needed.
f. If override switch contacts are not held open, check for loose or defective pulse timer or improperly adjusted override switch.

MOTOR OPERATES AT LOW SPEED ONLY (OPERATES PROPERLY IN DELAY & PARKS PROPERLY)

1. With ignition on and wiper switch in high position, disconnect electrical connector to gearbox relay, Fig. 5, and connect test lamp between terminals 2 and 3 in connector.
2. If lamp does not illuminate, repair wiper motor. Check for ground in shunt field.
3. If lamp illuminates, check for grounded wire between No. 3 wiper terminal and the wiper switch and, if satisfactory, check for defective wiper switch.

MOTOR OPERATES AT HIGH SPEED ONLY (WILL NOT DELAY BETWEEN WIPES)

1. Check for proper terminal contact at wiper motor connector terminal No. 3 and, if satisfactory, connect jumper wire from terminal No. 3 to ground, with wiring still connected to wiper motor.
2. If condition is still present, remove motor and check for open in shunt field.
3. If wiper has low speed and shuts off satisfactorily, check for open in lead between terminal No. 3 and wiper switch and, if satisfactory, check for defective wiper switch.

BLADES CYCLE IN & OUT OF PARK POSITION WHEN WIPER IS SHUTOFF

1. If wiper has both low and high speed, replace park relay.
2. If wiper has high speed only, check for proper terminal contact at wiper motor connector terminal No. 3.
3. If contact is satisfactory, with wiring still connected to wiper motor, connect a jumper wire from No. 3 terminal to ground.
4. If condition is still present, remove motor and check for open in shunt field.
5. If wiper has low speed and shuts off satisfactorily, check for open in lead between terminal No. 3 and wiper switch and, if satisfactory, check for defective wiper switch.

MOTOR INOPERATIVE IN DELAY MODE (WIPERS FUNCTION IN LOW OR HIGH SPEED)

1. Disconnect wire from No. 6 terminal and, with wiper switch in mid-delay, connect one lead of ohmmeter to to wire from terminal No. 6 and other lead to ground and set ohmmeter to megaohm scale.
2. If there is no resistance shown, replace wiper switch.
3. If there is resistance shown, replace timing circuit assembly.

WIPERS RUN CONTINUOUSLY IN DELAY MODE (WILL NOT DELAY BETWEEN WIPES)

1. With ignition switch on, operate wipers in low, medium and high speeds and check whether wipers shutoff properly.
2. If wiper has high speed only, refer to MOTOR OPERATES AT HIGH SPEED ONLY (WILL NOT DELAY BETWEEN WIPES)
3. If wipers will not shutoff, refer to WIPERS WILL NOT SHUTOFF, BLADES OPERATE IN NORMAL WIPE PATTERN.
4. If wipers operate properly, but do not delay between wipes, ensure wiper switch is adjusted to mid-delay position and wipers are operating, then disconnect lead from terminal No. 6.
5. If wipers stop, check for grounded circuit between terminal No. 6 and wiper switch and, if satisfactory, replace wiper switch.
6. If wipers continue to run, remove washer pump cover and reconnect all wiring to wiper motor.
7. With wipers running continuously in delay mode, disconnect lead to timing circuit from pulse relay.
8. If wipers stop, replace timing circuit assembly.
9. If wipers continue to operate, replace pulse relay.

INTERMITTENT OPERATION-BLADES STOP RANDOMLY DURING OPERATION

1. Remove wiper system fuse and connect ammeter across fuse terminals.
2. Operate wipers at low speed while observing current draw on meter. Readings will fluctuate.
3. If lowest reading is 5.0-6.5 amps, replace circuit breaker and brush plate assembly.
4. If lowest reading exceeds 6.5 amps, replace wiper blades and repeat test.
5. If lowest reading still exceeds 6.5 amps, disconnect linkage from motor and repeat test.
6. If current draw is less than 6.5 amps, repair binding linkage. If current draw exceeds 6.5 amps, repair or replace motor.