Intermittent Wiper System
Fig. 6 Body Computer 25-way Connector:
To diagnose system malfunctions that do not involve the delay function, refer to TWO SPEED WIPER SYSTEM.
EXCESSIVE DELAY OR INADEQUATE VARIATION OF DELAY
1. Normal operating range of the delay switch are 1/2 second to 30 seconds. If delay is outside these parameters, remove wiper motor wiring harness while motor is parked in the Off position
2. Remove 25-way connector from body computer, and set wiper control to maximum delay position.
3. With ignition on, measure voltage between pin 9 and metal case of body computer.
4. If voltmeter indicators zero volts, go to step 6. If 10-15 volts remove wiper motor circuit fuse and using an ohmmeter, measure resistance between pins 9 and 22 of body computer with wiper control first set at minimum, then at maximum delay.
5. If resistance at minimum setting is 0-15 ohms, and 240K-330K ohms at maximum delay setting, replace body computer. If resistances are not as listed, replace wiper control switch.
6. Set wiper control switch to minimum delay setting and measure voltage between pin 9 and metal case of body computer. Zero volts indicates open in intermittent wipe wiring circuit. If 10-15 volts are present, replace wiper control switch.
Fig. 5 Wiper Switch 8-way Connector Dynasty & New Yorker:
WIPER DO NOT DELAY WHEN IN DELAY POSITION
1. Verify that the motor will park when switch is turned off.
2. Disconnect 8-way wiper connector in steering column and connect jumper wire from pin 8 to pin 5, then connect another jumper from pin 5 to pin 1.
3. Connect a voltmeter or test lamp between pin 2 and a good ground. Voltage should be present, pulsing at 2 second intervals for a duration of 1 second. If voltage is constant, remove 25-way connector from body computer.
4. If voltage is still constant, wiring harness is shorted. If no voltage is present, move positive lead of voltmeter to pin 10 of 25-way connector.
5. If voltage is present, check for short in wiper pump circuit. If there is no voltage, the body computer is shorted.
WIPERS DO NOT OPERATE WHEN SWITCH IS IN DELAY POSITION
1. Disconnect 25-way connector from body computer and place wiper control in maximum delay position.
2. Connect positive lead of voltmeter to pin 9 and negative lead to metal case of body computer.
3. If voltmeter indicates zero voltage, check control switch and wiring for open circuit. If 10-15 volts is indicated, connect positive lead of voltmeter to pin 22.
4. If voltmeter indicates zero voltage, check control switch and wiring for open circuit. If 10-15 volts is indicated, connect positive lead of voltmeter to pin 24.
5. Disconnect wiring harness from wiper motor and set control switch to Low position.
6. If voltmeter indicates zero voltage, check wiring harness to body computer for open circuit. If 10-15 volts is indicated, replace body computer.
WIPERS DO NOT PROVIDE AN EXTRA WIPER WHEN WASH CONTROL IS RELEASED
Replace body computer.
WIPER DO NOT RETURN TO PARK
1. Verify that motor will park when switch is off.
2. Set wiper control on maximum delay, then between wipes when blades are at rest, disconnect 25-way connector from body computer.
3. Connect positive voltmeter lead to pin 20 and negative lead to metal case of body computer.
4. If voltmeter indicates zero voltage, check for open in wiring. If 10-15 volts is indicated, check for continuity between pins 20 and 24 using an ohmmeter.
5. Reverse leads of ohmmeter between pins 20 and 24 and check continuity again. If there is no continuity in either direction, replace body computer.
WIPERS FAIL TO RUN WHEN WASH CONTROL IS OPERATED DURING DELAY MODE
1. Disconnect 25-way connector from body computer, then connect voltmeter positive lead to pin 10, and negative lead to metal case of body computer.
2. Set wiper control to delay position and depress wash switch.
3. If voltmeter indicates zero voltage, check switch and wiring. If voltage measures 10-15 volts, the body computer is defective.
WIPER START ERRATICALLY DURING DELAY MODE
1. Verify good ground at instrument panel and motor ground strap.
2. Verify good wiring connections at body computer, wiper motor and wiper switch.
3. If condition persists, replace body computer.