My wipers have been acting up since a few months ago when i got on a bumpy old muddy road at the farm..I was cruising through a pasture and took a few good bumps and my wiper switch started on fire filling the cab with smoke so i ripped the cover panel off as fast as i could and cut the ground wire, went to the junkyard and got a good switch, installed it and all was fine except the intermediates....They work on and off, some days they work for about 10 minutes and they stop half way in the windshield and i have to use the full time switch to take them off....when i use the full time wiper selection and go to shut them off they stop where they are...they don't end the sequence at the bottom of the windsheild. Is this possibly a relay? It also started clicking once every rotation on the firewall just today? what could this be?

 

ill bet you the plug is just loose or worn mine does that from time to time all i do is unplug the wiper motor and plug it back in

 

I will give it a shot...i have to go to Minnesota tomorrow so it'd be in my best interest to have them working as it'll be raining up there and that horrible screeching noise from the wipers on a partially dry windshield on high speed mode is annoying as H#LL

 

Alright, tried unplugging and plugging in the motor connections and still does it...cleaned them too...still the same...any other ideas?

 

I think your wiper relay is down by the park brake, follow the wire from the switch....... I could be wrong.

Old post saved......
After viewing several posts on wiper problems I decided to tackle the "black box" wiper delay control under the dash. After I got the thing out , unplugged, and in my hand I pulled it apart as described in other posts and I found just what I was told I would find, broken solder joints (3) connecting what appears to be a switch/relay mounted on a sheet metal "platform" with 2 "wings" (heat sinks?). The 3 jounts connect the switch and the 2 legs of the "platform" to the circuit board. I re-soldered the connections, flipped the board over and then used JB weld to glue the legs of the "platform" down to the board and used a big dab to glue the side of the platform to the side/end of the black "cube" which sits next to the platform on the board. This glue job will help the platform stay in place under vibration better than the weak solder joints in the stock set up(I hope). Hard to describe but if you open the box (2 screws) you will see what I am describing pretty clearly. I re-assembled the board in to the box, reversed the metal mounting bracket (used same holes in box and bracket but rotated it 180 deg.) Then re-mounted the unit under the dash in a place well away from vibration (I hope). I used a rubber washer (made from an inner tube) between the truck and the mounting bracket this should keep vibration down (I hope). I now have two (2) constant speeds: slow and " a little faster", and I also have my intermittent settings back

 

Mine does the same thing and if I rotate or tap the switch, it starts working again so if either happens with you I would say swap out the switch.

That "fire and smoke under the dash" thing is something I experienced once on an older 460 powered F350 work truck.

I just cut the melting wire (after dragging everything out of it that was mine) and it stopped!
The funny thing is that I could not see anything different as everything electrical still worked!

 

Okay, so i'll check out the "BLACK BOX" first and see if thats all intact, and if so then i'll splurge and get the new switch...i appreciate all the help! I'll post back and let yall know what i find.

 

My 91 F150 does the same thing. I replaced the switch and it still does it. I am going to try the black box trick..sounds like that is both or our problems..good luck with yours Joe

 

When mine had that problem it was hiding in plain sight and an aggravating ordeal checking everything. One of the wires going into the wiper motor was corroded and making intermittent and/or poor contact and heating up. If I recall there are three going into it. Easy enough to check anyway. Good luck.

 

Ok thanks man, i will check that too

 

I wanted to put my input in on this with what happened to my wipers. My wipers on my ‘84 f250 stopped working completely. So I got my test light and tested all the wires plugging into the wiper motor and they were all dead. So where I looked first was this plastic electrical connection that connects to the back of the wiper switch right by the parking brake. I had one of my wires there wear out and it actually pulled the wire completely apart. I just stripped the wire and shoved it back into the terminal with some tape and it’s working fine now. Hope that might help anyone in the future looking for answers.

 

I am having a similar problem with my 1985 F-250 where the wipers will work on their slow and fast speed but there is no intermittent. This is very annoying trying to reach down and turn the wipers on and off. Not to mention when you shut off the wipers they will stop wherever they lie on the windshield. The guy who replaced the original wiper motor said "there is a module in the dash", would he be referring to this so called black box that you guys are speaking of? If so where exactly is it located and how hard is this issue to fix?

 

Yes thats the black box. Not exactly sure how to describe the location, if you take out the wiper switch, just follow the wiring and you'll find it.
Most likely there is a broken solder connection inside, very easy to correct by reheating it and maybe adding a touch more solder if needed. I believe the connections on each side of the box are the same, so you can remove it entirely to work on it, and plug the wires back in to at least get high and low speed while you're tinkering or looking for a replacement.