Pulse / Delay / Intermittent Windshield Wipers

[Schurkey]

I'm borrowing a friends '89 K1500 extended cab while my '88 is down with a popped engine. Part of my "rent" is that I get to fix about a thousand things that are broken or non-functional on this vehicle.

Today's successful project was to get the windshield wipers functioning reliably. The wipers haven't been reliable for months. This became a priority as yesterday it POURED ALL FRIGGIN' DAY and Rain-X wasn't handling it.

The wipers would work...sometimes. They might work for several miles then quit, they might not work for miles--or days--then start up again. There was no pattern, and twisting/pulling/wiggling the Multi-Function Stalk did nothing productive. When I started work on this thing, the wipers were totally dead--no pulse, no low speed, no high speed.

I disconnected the 5-wire molded plug from the motor under the hood, and stuffed a test light into each of the five connections in the molded wire harness end that plugs into the wiper motor. I had some power, I had some ground. I plugged the connector back in, and pushed 'n' pulled on it a little. The wipers would work as long as I applied pressure. I took a wild guess, and bought a wiper circuit board. About $30.


In one place, it says "Remanufactured". In another, it says "New". I think the thing is new, not reman--But I don't know for sure. I really hate "Made In China". But what am I gonna do?




Well, I pulled the three Torx-head screws that hold the cover on. They also hold the circuit board "in". The board pulls right out other than some friction from the three connections at the lower left in the photo below.

The grease inside was hard. I added some fresh onto the worm gear at the very bottom. The grease you see in this photo is original.

On a whim, I grabbed a magnifying glass, and looked at the solder joints on the original circuit board. The first ones I looked at were the six solder joints nearest the harness connector. (lower, right side in photo below.)

There's one that is covered in Conformall, a moisture/weather barrier--the red blob near the "Pulse" molded-plastic harness connector. It's the same red crap on the left side of the board. I could see--with the magnifying glass--that the solder joints were broken on three of the six connections close to the harness connector, next to the red blob.



Three minutes with a soldering iron, some rosin flux, and two inches of thin-gauge solder. Six joints re-flowed. I did a quick inspection of the other joints that didn't have the red Conformall on them and they seemed OK. I left 'em alone.

There are two "arms" that make contact with the big, round disc in the motor housing. They're on the back-side of the circuit board, and I don't have a photo of them. One was covered in hardened grease. I cleaned 'em both, and I bent them "up" for more pressure on the disc.

I slapped it back into place, put the screws into the cover and tightened. Snapped the wire harness into place.




POW! Wipers work just like they should. Every time. Pulse, low-speed, high-speed.

Fixed.

All that's left is to return the Chinese circuit board to NAPA for a refund.

[Blue Bowtie]

Pretty common. I've had to do that on both my half-trucks and one Astro. Good documentation!

[brcidd]

Very very common- I've been doing this fix for 20+ years.....