In the Cherokee I just purchased, the owner stated that the windshield wiper motor was shot. I successfully remove the motor (without snapping a single rusty bolt - imagine that) but before I buy a new motor, is there any way to test this one so that I see that it's definitely the motor and not the switch, wiring, etc? Thanks

 

Put it back, turn the wipers on, use a multimeter

 

Rawk,

I'm a carpenter - what does that mean in novice terms? I can hook it back up to the power connection without reinstalling it. But then I'll have to go buy a multi-meter (not a big deal, any recommendations for a novice version?). Once I get the multi-meter, how do I hook that up to the motor?

Thanks for keeping it basic for me.

Woody

 

http://www.harborfreight.com/7-funct...ter-98025.html

 

Woody,

You won't be putting it back. You will be testing for voltage at the front wiper motor connector.

When you get your digital voltmeter read about how it works then test on your battery. Select "20" on the DCV scale, touch the meter red probe (+) to the battery positive (+) post and the meter black probe (-) to the battery negative (-) post. What you see is the static battery voltage. Write it down.

Remove the electrical connector from the wiper motor and look at the end of it. You should see 6 pin cavities, arranged and numbered like this:

3 2 1
6 5 4

You'll be checking for battery voltage at pin sockets 1 and 4, 5 and 4, and 6 and 4. 4 is ground and 1, 5 and 6 are power.

Turn the ignition key to Accessory or RUN (engine not started).

Touch pin socket 1 with the meter red (+) probe and pin socket 4 with the black (-) probe. 1. With the meter set at 20 VDC, you should see the battery voltage. 2. If not, keep the red probe on pin cavity 1 and touch the black probe to a bare metal spot on the body. Here you should see battery voltage.

If you don't see battery voltage in either test 1. or 2., the Circuit Breaker for the wiper motor is tripped. If you do see battery voltage the CB is okay.

If you see battery voltage in test 2. only, the ground circuit for the wiper motor has high resistance (corrosion) or the circuit is open from a broken wire.

Next, turn the wiper switch to Low Speed. Probe pin cavity 5 with red probe and pin cavity 4 with black probe. You should see battery voltage. If not, try pin cavity 6 to pin cavity 4 with the wiper switch to High Speed. If you don't see battery voltage at pin cavities 5 or 6 when doing these tests the wiper switch may be defective.

If these tests show that you have voltages at these connector pin cavities it's safe to say the motor is defective.

 

I should have added to post #5 that if the CB is tripped it could be caused by a shorted wiper motor or a short in the wiper motor control circuit. If tripped, the CB has to be replaced prior to testing at the connector.

I'm not that familiar with the '94 XJ, but per the '94 wiring diagrams the CB is rated at 4.8 Amps and is located near the turn signal flasher.

 

CCken,

Thanks so much, will be doing this all tomorrow. I appreciate the detail.

Thanks,
Woody