Good morning,

I am new to the FTE forum. My name is Frank. I am a disabled 50-something shade tree parts changer and I am looking for some assistance diagnosing an issue I am having with my 1986 F-150's intermittent wipers.

When the wipers are on continuously - either low or high setting - they will run briefly, then stop about mid window. They will remain there until I fiddle with the wiper switch a bit, returning it to the stop position. The wipers will then return to the park position. This issue does not occur when the wipers are on in any intermittent setting.

Thinking about this issue and after having read many, many posts on this forum about problems with intermittent wipers, I strongly suspect the issue resides with the intermittent wiper governor circuit. When on for a brief period, something gets hot and shuts the wipers down until it cools off - like a circuit breaker if there were a circuit breaker involved instead a fuse. It could also potentially be the ground for the governor circuit as well I suppose.

Does my reasoning make sense to those of you who are more experienced troubleshooting electrical issues? Am I missing or ignoring any other high probability items?

I appreciate any assistance you all can provide me!

Frank

 

Sounds perfectly reasonable to me, and welcome to FTE!

Others here will know better than me since I'm not positive but I believe there might be
a circuit breaker in the switch assembly and, if there is, it might be doing its job (which
is to protect the wiring) and reacting to an overheating situation caused by bad
connections or loose wiring or worn-out components or something similar.

Let us know how it goes and what you find, ok?

 

I would take the switch from the plug and check for any corrosion on the metal pieces, because if too much corrosion is built up on it, it could be keeping the power from reaching it's point.

See what i'm saying?


Also, I have an '85 F-150, so we've got about the same truck!

If you've got anything you wanna ask, just send me a message, or just post another thread!

 

I believe I get what you're saying Wicked Endings, but I have a question: What is the best way to remove any corrosion that might be present? I imagine abrasive cloth would not work in this situation.

Frank

 

Frank,

To clean this, take a knife and scrap any buildup on it. They are only metal strips, so if you take a knife and clean them off, that'd be fine.

Abrasive cloth would be fine, too, but the knife would work just as well.

 

This evening, I found a Mitchell shop manual for my truck that I could buy for a reasonable price and download. It is awesome! As it turns out, the wipers are protected by a circuit breaker that is integral to the switch.

Also, I drove the truck home from my sister's place in the rain today and I noticed something interesting: When it was raining heavily and the wipers were on continuously, they didn't stop mid windows as I had told you all previously. However, when the rain lightened up and the windshield was relatively dry, the wipers would stop mid windshield until I fiddled with the switch. This makes me wonder if the increased drag caused by the wipers on the dry windshield could be causing the switch to overheat and blow out the breaker? What does anyone think?

I got a can of electronic contact cleaner and tomorrow I'm going to clean the switch contacts to see if that will help.

Frank

 

Interesting....

Sounds like something to follow up on!

 

I would say you are right. The circut breaker is tripping. Check the ground at the wiper motor, and the ground at the intermittent switch.

It may be time for a new wiper motor.

 

Right now, I am working on getting the cruise control working again. Unfortunately, I don't have a garage (heated or otherwise) to work in, so I spent most of my afternoon in the cold, sleet and snow with my head jammed up under the dash measuring the resistance values for the switches. The issue with the wipers is up next. I did not prioritize this project since the windshield wipers do work, just not as reliably as I would like.

You mentioned that it might be time for a new wiper motor. Curiously enough, the previous owner had the wiper motor replaced just before I bought the truck.

I will check the wiper motor's ground and the switches ground as well as cleaning the contacts as soon as I thaw out a bit.

Frank

 

Another thing to check is the firewall to engine ground cable.

Without that cable, or it being in good condition, the wiper motor, dash components, cruise control etc... wont have a proper ground anyway.

Just a thought. The wiper motor, cruise control, radio, instrument cluster, wiper switch, dash lights, etc, ground through the dash and firewall, and from there ground through the cable to the engine, which from there goes through the negative battery cable to the negative battery post.

You may need something as simple as a new switch as well. The circut breaker may be old and tired. Be good to rule out other possibilities first.

 

Glad I searched and found this, Ran A wire straight from the Battery GND to that wiper motor and now my wipers function correctly again! Thank You! See it always pays to search before posting!

 

Glad you got your problem fixed.