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1991 C/K Wiper Motor going bad?

GM Guy

GM Guy

Manual Trans. 2WD Enthusiast
Messages
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Location
NW Kansas and SC Idaho
On my 1991 in signature, the wipers are unreliable. sometimes they fully work, sometimes only on high/low, no delay, and sometimes not at all. Is this a wiper motor going bad?

I've also heard something about the wiper ciruit board having problems?!?!? (idk what it is about)
Also, would this be switch related, or relay related?

Would buying a new wiper motor solve this problem?

Any input appreciated, thanks!
 
GM Guy said:
On my 1991 in signature, the wipers are unreliable. sometimes they fully work, sometimes only on high/low, no delay, and sometimes not at all. Is this a wiper motor going bad? Perhaps

I've also heard something about the wiper ciruit board having problems?!?!? (idk what it is about) Yes...they had problems with bad boards etc
Also, would this be switch related, or relay related? Either

Would buying a new wiper motor solve this problem? Maybe

Any input appreciated, thanks!
Click to expand...

Pull the motor first, get it tested if possible.
 
Sometimes the soldered connections become cracked on the circuit board and need re solder to repair them. You could try that before buying anything..
 
DEERE3594 said:
Sometimes the soldered connections become cracked on the circuit board and need re solder to repair them. You could try that before buying anything..
Click to expand...

Yu betcha DEERE! I've done that exact repair on my '92 6.2 diesel years ago. Worked slick. Easy repair that saved me 100 bucks at the time.
 
my bet is the wiper module on the fire wall. I have had to replace a couple of them.

try this, when they don't work, open the hood, bang on the wiper module box with your fist, if they start working, thats the problem.
 
SSduramax said:
my bet is the wiper module on the fire wall. I have had to replace a couple of them.

try this, when they don't work, open the hood, bang on the wiper module box with your fist, if they start working, thats the problem.
Click to expand...

is the circuit board part of the wiper module? Also, about where is this located(board and/or module)? (truck is currently on the road w/ parents currently, so i can't look at it)
 
Board is on wiper motor, drivers side firewall. 3 torex(stars) screws hold on the cover, then it "slides" out...
Let me know if you need pics, I dont have a camera but I know where I can find some...
 
ok, think i got it, so just check for cracked soldering on the board, right?

What about that module on the firewall, is it a common problem too?
 
I would say the module is pretty common as it has happened to two different trucks of mine and when I asked my cousing (who back in the late ninetys was a tech at a dealer) he said he saw it alot and diagnosed mine in about two seconds.
 
would that module have anything to do with the delay setting? The wipers rarely work on delay, but almost always work on high.

Also, is the module about in the center on the firewall?
 
Last edited:
I am 99% sure you need the circuit board in the wiper motor Deere was talking about. It is a very common problem with those trucks. You can resolder the terminals mentioned above or replace the board itself. I think you can buy the boards aftermarket now. Check your local parts stores they should be considerably cheaper than the dealer.
 
You can get a new board at autozone for under 40 bucks if I remember right...
 
Finally, favorable testing conditions have shown up. (aka, dry western KS finally gets rain to test wipers while truck is on the road. it is dry, about 5 inches behind for the year, only have about 5 inches to date, normal yearly rainfall is 18 inches)

sorry it took so long, but it rarely rains! anyway, turned wipers on in a light rainstorm, and delay and low would only work after going over a small bump in the road, high worked the whole time. Got out and rapped on the motor (actually the circuit board cover on the end of the motor, correct me if i am describing the wrong part) after rapping on it, it worked, so i feel that it is a circuit board.

also, there doesn't seem to be a separate module, just a wiper motor sticking out with the circuit board and its cover.

is there a separate part # for the board? as the local GM dealer seems to only list an assembly of the board and the motor.

this would surely be symptoms of a bad board, or at least one that needs repaired, correct?
 
OK, I am at college, and so that means a new dealer. I am impressed, as I described the symptoms and the parts guy ran out back and came back w/ the board.Said that this has solved all problems. It is an updated number, so that hopefully means better design. Apparently the other dealer didn't look hard enough, or something, as they had no idea what i was talking about.

Anyway, I bought the board and I am installing it tomorrow. only things needed are a torx screwdriver, patience and dielectric grease, right? How much dielectric grease should be installed?

Sorry this thread has drug on so long, but i guess its better than starting a new one. :thumbsup:
 
anyone know how much dielectric grease to put on?

also the instructions say to apply sealant to the cover. Is black RTV adhesive/sealant all right, or is something else reccomended?
also, do i follow directions and go all the way around, or should i leave a gap at the bottom? how well does the motor seal, would it be wise to leave the bottom alone for drain purposes or is it OK to seal it all up?
 
There's a picture of a bad solder joint here:

I re-soldered both my chevys... and didn't use any sealant at all, either time. That was a few years ago. No problems since then.
 
it won't hurt any to seal it, will it? Or would it be best to leave wel enough alone?

How much dielectric on the plug? just a little bit on the terminals?
 
I would leave it alone, thats just me though... Yes not to much grease
 
I guess it is better to let it breathe, rather than try and seal it. I think i will heed you guys' advice and not seal. heck sealing it might make it weatherproof. (my experience w/ weatherproof is that the water goes in, not out. waterproof keeps out!)):h
 
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