Windshield Wiper start on their own

Maintenance/Repairs
1

Hello,
I hope that I can find someone to help me, I’ve 2007 Chevrolet Trailblazer, around a month ago the front Windshield Wipers started to start on their own, when I got the car checked the technician told me that I’ve to replace the Windshield Wiper Motor, I wonder if this is correct? and what would make the motor to starts on its own?

Thanks in advance, have a good day.

2

A faulty control board in the wiper motor unit does this. Replacing the unit fixes the problem and is much more cosr effective than trying to fix the fault.

3

The wiper motor doesn’t need replacing because it works.

The problem might be with the wiper motor pulse board.

http://www.rockauto.com/catalog/moreinfo.php?pk=982854&cc=1433505

The pulse board controls all the wiper motors functions.

One thing to try is turn the ignition switch on without turning on the wipers. Open the hood and on the wiper motor push on the pulse board cover. If the wipers operate the pulse board is the problem.

If the wipers don’t operate, then the problem might be in the multifunction switch.

http://www.rockauto.com/catalog/moreinfo.php?pk=1481934&cc=1433505

Tester

4

Thanks Tester for your prompt feedback, as soon as I turn the ignition switch on the wipers start to work on its own.

5

Thank you guys for your help, I really appreciate you prompt reply, but is it possible to find a replacement of the board only, without having to replace the entire motor?

6

This is th pulse board that is bought separately. http://www.rockauto.com/catalog/moreinfo.php?pk=982854&cc=1433505

7

Thanks guys really appreciate your help, take care.

8

Let us know what happens when you get it fixed.

9

HI,
I want to thank you very much for your comments here, I got the part from ebay from “alldayparts” for around USD 82 + shipping as I couldn’t find it in any parts stores in my area, and I installed it all by my self.

Thanks a lot again.

10

If you take a look at the old board under a magnifying glass you may find one or more solder joint that has a crack in it. That’s a common cause of PCB’s failing in cars. The material the metal layers are made of has different thermal expansion than the PCB material itself. This would happen on your home computer too, except that home computers don’t experience the extreme temperatures in cars, not to mention the jostling.

If you see solder joints cracked, you might want to keep the old board around in case you run into this problem again. Sometimes it is possible to fix a cracked solder joint by simply re-soldering it.

Glad you got your wipers working again. $82 is a bargain. Best of luck.

11

Thanks George, that’s really a excellent advice, I’ll try it and I’ll post the results.

12

I tend to think you aren’t going to be able to find the trouble visually. Usually, the type of trouble you describe is due to a faulty component, not a bad circuit trace.