wiper troubleshooting

[Kellyboy]

Hi all, I am a proud new owner of an 86' M10008 and the wipers and washer are not working at all. I found that I had no conductivity between the wiper motor case and the vehicle ground. I took the grounding strap off and cleaned it and reinstalled. I now have conductivity from the wiper motor case and frame but still no dice. just wondering if someone can tell me how to determine weather it is a wire or motor problem. I think the 3 wire plug is the one that powers the motor and I have 12v present on one of the prongs to ground. I don't want to just start putting 12v to random prongs on the motor in fear of burning something up and not sure what prongs I should expect voltage on the wire harnesses.
thanks.

 

[Kellyboy]

I also bought a new wiper motor for a k30ruck and it only has sockets for two plugs rather than the three the original one has. any ideas what the third plug does?

 

[mike634]

I just replaced my wiper motor and it had hook ups for all 3 plugs. Check to the right of the motor to see if these noise suppressors are hooked up. If they are, by-pass them and see if that helps. If I remember right the third plug is to set the wipers on the bottom of the windshield when you turn them off

 

[cpf240]

Are you buying parts for an '86? All CUCVs are based on '84 parts, and that is where you should start. There are very few exceptions to this, like the seat bases in the later M1009's.

 

[GunnyM1009]

I had the same problem with my wipers. I thought it was my switch but it turned out to be the moving parts behind the main outer firewall had froze from corrosion. Sprayed with chain oil. Cleaned and dioelectric greased all my plugs and removed the three noise cancelers and all is well now. Hope yours turn out as easy.

 

[Kellyboy]

[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Thanks for the replies mike,gunny, and cpf. I am getting somewhere. I learned to source the parts for an 84 and when I apply 12v and ground directly to the motor both speeds work even when feeding through the resistors. I also verified the switch is working by taking a reading on the plug when operating the switch however I only get 10v on both settings. Seems like the motor would at least grunt a little but it does nothing. Also when testing for voltage when operating the washer I only get 1v. I am going to clean all connections tomorrow with hopes of getting 12v. Fingers crossed that I don't have to pull apart the steering column to clean those. The good news is I don't believe I will have to buy any parts. Anyone with questions on how to do the test I will be happy to help.[/FONT]

 

[cpf240]

Have you pulled apart and cleaned the bulkhead connector on the firewall? Almost all the connections between the engine compartment harness and the fuse box / dash harness go through there. After all these years, whatever GM sealed it with turns to goo. A good cleaning and some dielectric grease can do wonders...

 

[Kellyboy]

I have not pulled the bulkhead connector. I will definitely do that tomorrow and let y'all know how I made out. Thanks.

 

[MarcusOReallyus]

Also when testing for voltage when operating the washer I only get 1v.

You are on the right track. You have high resistance somewhere in that circuit. When you measure the voltage with no load on it, you see 12v. Put a load on it and the voltage drops. Classic.

Bad or grungy connector, corroded wire or switch. You'll find one or more of those somewhere in the circuit.


TIP: Split the circuit.

Now you know a spot where there is 1v, so your problem is somewhere between that point and the battery. Find some point roughly halfway between, and test there while operating the washer. If your joltage is 12v, you know the problem is between that point and the washer motor. If the joltage is 1v, the problem is between that point and the battery.

Get the idea?

 

[Kellyboy]

Have you pulled apart and cleaned the bulkhead connector on the firewall? Almost all the connections between the engine compartment harness and the fuse box / dash harness go through there. After all these years, whatever GM sealed it with turns to goo. A good cleaning and some dielectric grease can do wonders...

I am trying to remove the bulkhead connector inside. Removed the two bolts that hold it but the fuse panel won't separate. Am I missing something or should it just pull apartment? Don't want to break it.

 

[Kellyboy]

Got it! There was a bolt in the center that on the outside that holds the connector together. Things are pretty cruddy in there. Gonna give it a good cleaning.

 

[MarcusOReallyus]

CRC Contact Cleaner is what you want to use. Good stuff. Don't use brake cleaner.

 

[cpf240]

CRC Contact Cleaner is what you want to use. Good stuff. Don't use brake cleaner.

And then a good coating of dielectric grease to finish it off..

 

[Kellyboy]

Thanks marcus and cpf. I was wondering about brake or carb cleaner. Will be getting some contact cleaner and dialectric grease. I have tead a tiny drill bit in reverse will clean the female connectors but seems sketchy. Anyone tried this?

 

[Kellyboy]

*heard

 

[MarcusOReallyus]

Ew. I would be leery of sticking a drill bit in there. Too easy to mess things up. I found some great pipe cleaners that have hard nylon (I think) bristles intermixed with the usual softer stuff, and work well for cleaning things out. I think one of those chucked in a drill might just do the job. I don't remember where I found them, though. They are kind of like these.

I have not yet pulled my fuse block apart, but I have read there's a thick black goo in there that GM used to prevent corrosion. If you run into it, and the CRC contact cleaner doesn't cut that stuff, you might try a bit of throttle body cleaner, NOT carb cleaner or brake cleaner. It's supposed to be safe for most plastics.

 

[NovacaineFix]

Make sure you disconnect your batteries before doing anything, especially with a wire wheel on a drill or similar.

I did mine and used a small sandblaster to clean the terminals, but not sure if you have air available or a sandblaster. You'll notice that some of the terminals are vertical and some are horizontal, not the easiest to get to, especially near the retainer bolt.

Lastly, like everyone else has said, use a nice liberal amount of dielectric grease before putting it back together, don't use regular lube grease.
Good Luck!

 

[Kellyboy]

Well.....I thoroughly cleaned the bulkhead connections with contact cleaner, brushes, and picks..also coated liberally with dielectric grease. A real joy that was. Still no wipers. It was something that was desperately needed so it was not for nothing but.....considering just hardwiring in some switches on the dash because if I pull the steering column and replace the switch to no avail the love/hate relationship will strengthen for the worse. Oh well. "So you want a 30 year old CUCV do ya"? Lol

 

[MarcusOReallyus]

Well, you have the right attitude for a CUCV owner!


Now for some circuit splitting.

 

[cpf240]

Maybe this will fix it?