Questions and Answers

Jeep Grand Cherokee Wipers Q. Vehicle: 1994 Jeep Grand Cherokee Laredo, 4.0 liter, 4WD, automatic transmission. While driving in a recent ice storm, ice became packed under the wiper blade. The wipers still continue to work in the low and high speeds, but fail to operate in interval or when the washer button is pushed. (Normally engages for three wipes).

Also, the wipers do not return to the "nest" position when turned off. Where would this problem most likely be located? The motor? The switch? The relay? or is there another source?

Thanks for the help,
Robert

A. It is possible the linkage for the wiper arms are bent out of shape and thus would not go back into the park position. But it's easy enough to test the wiper motor. All you need is a DVOM meter.

To test the wiper motor, turn the ignition switch to ACCESSORY or ON. Position the wiper switch and probe the motor connector as indicated in the following steps.

1. Wiper switch in OFF position, measure resistance between terminal 4 and a good ground. Meter should read zero ohms. If not, repair wiring to ground.
2. Wiper switch in any position, measure voltage at terminal 1. Meter should read battery voltage. If not, repair wiring to intermittent wiper module.
3. Wiper switch in LOW, measure voltage at terminal 5. Meter should read battery voltage. If OK, but if wipers do not operate, replace failed wiper motor. If not, repair wiring to intermittent wiper module.
4. Wiper switch in HIGH, measure voltage at terminal 6. Meter should read battery voltage. If OK, but wipers do not operate, replace failed wiper motor. If not, repair wiring to intermittent wiper module.
5. Wiper switch in LOW or HIGH, voltmeter connected to terminal 2. Turn wiper switch to OFF and observe meter. Meter should read battery voltage when switch goes to OFF, then zero volts after wipers park. If battery voltage present, but wipers fail to park, replace failed wiper motor. If no battery voltage present, repair wiring to intermittent wiper module.