Wiper Issues

[IHateAutomotiveWirin]

Hi everyone, Im having an issue with my wipers not turning on.
I got this truck almost 2 months ago, 1990 K2500 (350TBI w/ Muncie 4 speed).
At first I was having intermittent wipers, sometimes they would turn on when I didnt want them on, other times when I did need them they would only work at delay and low. My multifunction switch feels really gummy but they at least worked up until this past weekend. Now Im getting zero response from my wipers at all.

I pulled the wiper motor and the pulse board and inspected it for damaged or burnt solder but it seems to be in good shape.
I even put the board in a new wiper motor (old style remanned) and it still refused to turn on.
Went through and cleaned and reattached all the grounds in the engine bay, and still nothing, and the 25A fuse is fine as well.

I have a steering wheel puller and am about to pull the little board thats in the steering column to inspect it, but Im really not sure where else to look.

Any pointers or some different places to look are highly appreciated, and are there any pictures I can post to help yall help me?

 

[IHateAutomotiveWirin]

Heres the front and back of the board from the wiper motor, the solder really doesnt look bad to me but I guess Ill re-solder Im just not sure where

 

[IHateAutomotiveWirin]

Now Im only getting 8.5 volts at the connector that plugs into the wiper motor, what in the hell could this be? Im honestly completely stumped

 

[someotherguy]

If you've replaced the circuit board with a remanufactured one, that *should* have resolved the issue, as most of the wiper problems on these trucks come down to the circuit board. The #1 failure on them are simply bad solder joints where the harness socket attaches to the board. There can be tiny cracks not visible without magnification that can still cause issues.

It's been a while since I messed directly with these so that old style motor (1988-1990) I'm not 100% sure what you should be seeing at the connector. Early, early trucks had the pulse module as an inline part in the harness between the wiper switch and the motor. Not a common item IIRC. My suggestion would be look in the factory service manual and follow the diagnostic procedures to see where your voltages should be.

Here's free downloads of the manuals - be sure to look at your specific year model.

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

The switch inside the column rarely goes bad, though a few people have had it crap out and lose all its detent positions, so you don't "feel" the switch as you operate it. If that's the case with yours then yeah, might be time to replace the switch. The breakdown of the steering column is in the factory manual as well. Beware - it's a little bit of a job. I'd exhaust other troubleshooting first before tearing into the column.

Richard

 

[IHateAutomotiveWirin]

Thank you for the insight, Ive read through multiple threads on folks different wiper issues and Im about to go to the junkyard in a moment and see if I can salvage a newer style wiper motor with the updated "horseshoe" shaped board.

I found the ground thats on the back of the block going to the frame looks a little frayed, but the rest of them are in good condition, but Im not sure how that could be the issue when everything else electronic seems to be functioning normally except the wipers.

And my switch I can feel the detents as I turn it but it feels gummy and sloppy, not solid clicks.

Im gonna just go get the wiper motor and install it anyway and swap that ground out too. Automotive elctronics and wiring are not my specialty.

 

[IHateAutomotiveWirin]

I swapped out the ground straps from the block to the frame and frame to firewall, and now Im getting 12.5 volts at the wiper motor plug, thank the Lord that issues solved.

Installed a new style wiper motor from a 96 S10, it already had a replaced pulse board from NAPA installed so I figured "this has got to be it". Well I put it on and still nothing, I know Im getting power through the connector because when I test it Im getting ~12.5 volts depending on where the switch is lo/hi/delay, so I know the current is flowing properly now, but I am completely confused.

I pulled the steering wheel and inspected everything, it all looks fine.

What are the chances of trying multiple motors/boards and they all fail? I was banging on the motor while it was on high kinda like a messed up starter and still nothing at all.

What do you guys think? Is there anymore pictures I can post to help yall help me?

 

[GoToGuy]

You have power available , but you select where it goes that's the area to check.

 

[Ron88]

If you suspect the switch you might be able to plug a new one in without having to install it in the column . I was able to on my 88 with no tilt column can't be sure about a 90 or if you have tilt,but someone may know.