Rick's Free Auto Repair Advice

Intermittent Wiper problems

Fix Intermittent Wiper problems

If you’ve got intermittent Wiper problems on a Dodge Caravan, Voyager, or T&C, the problem may be the multi-function switch on the steering column, the body control module, and the wiper relays. The multi-function switch contains 8 resistors, each for a different wiper speed. Start your diagnosis with this switch. Connect a digital ohm meter to terminals 6 & 7 of the multi-function switch. In the OFF position, you should see no continuity. In Delay 1 you should read 792-8080 ohms, 2= 5940-6060, 3= 4455-4545, 4= 465-3535, 5= 2475-2525, 6= 1485-1515, Low=990-1010, and High=90-1010. As an
alternative, you can test the voltage coming from the wiper switch. Voltage should range from 1v to 3v as you rotate the delay knob.

The delay varies depending on vehicle speed. At 10MPH or more, the delay varies between ½-16 seconds. At less than 10MPH, the delay varies between 1-36 seconds. This is controlled by the BCM.

Before you suspect the BCM, check the dark green/white wire at the wiper motor. The voltage on this wire should go from 12v to 0v every time the wipers return to the bottom position on the glass. This happens because the wiper motor is actuating the park switch built into the motor. If it is not switching, the BCM cannot control the delay. The only fix is to replace the wiper motor.

 

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat



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