91 TC - Windshield Wipers won't work

[walt03]

I bought a new wiper motor and installed a new multi-switch control. Both those work and the multi switch "ohms" out to the factory manual specifications.

I've been trying to find the wiper control module under the dash but can't locate it. I've found the 2 air bag modules, anti lock brake and chime modules and something called "auto lamp". Could this be behind the ash tray or radio. I've only pulled the dashboard panels on the drivers side.

The only thing left is the wiper module but I can't find it and don't know how to check it out if I did. If power goes through this module to the wiper motor it may be the culprit as there's nothing else left.

No voltage exists at the wiper motor on the 3 prong harness terminal when the ignition swich is "on" and the multiswitch calls for the wipers to come on.

Any help from the experts would be appreciated. Rain-X won't help me in the snow
Thanks

[junk yard doggie]

Hi Walt

Let me know if that replacement wiper module gets the wipers going again.

Mike

[CivEZ]

So, the front windshield wiper module is actually attached to the windshield wiper moter. This module is called the "Pulse" module. It controls the pulsing or "speed" of the wiper.

Open the hood, look toward the center back, you'll see the motor for the wipers. The module is bolted onto the motor. You dont HAVE to take off the whole motor to get at the module. But I did. See the attached pictures.

There is a known problem that GM had with this module. The circuit board would basically short out. If you are luck the short is somewhere on the back of the board. But there have been cases of multiple shorts in locations not visible. (See my attached pictures for an example of a short).

I chose to go to O'riley Auto Parts and buy a new module for $30. I tried to solder the short, but I still had no luck, and I'm thinking there was a short somewhere else that I couldn't see. The new one worked like a charm.

Note: If you DO take out the entire motor. When you put it back together, make sure your motor and gears are set properly before attaching your wiper blades. E.G. Make sure your gears are back to their "neutral" position so that when you re-attach the blades the blades actually turn the full 90 degrees and don't get stuck/stop because the gear connecting to the motor isn't set correctly.