Wipers won't shut off after replacing MFS and GEM and highbeams not working properly

[JohnW]

The truck had the wiper problem when I bought it a couple months ago off of a buddy. It's a 1995 4cyl 5 speed 2wd ex cab. He's a mechanic and replaced the GEM module first with a new one (made in Mexico in 2010 according to the tag on it), then the switch. He said he thinks the old switch could've shorted the new module. He also swapped the wiper motor for a different used one. He parked the truck because after fixing other problems the clutch master went. He just got sick of working on it and never tore into it any further. The wipers work fine on low or high, but stay on low when you go to intermittent or off until the ignition is shut off. When you just turn the key to run or accessory, they work properly. But once the truck has been started and the wipers are turned on, they won't shut off.

I went to a junkyard and got another GEM module and put that and the new MFS in while the battery was disconnected. Still acts the same. I tried swapping the run/park and hi/low relays with no change either. The new GEM module is from a 96 (OBDII vs OBDI) but it acts exactly the same as before I swapped it.

The only things I can think of are that there could be a bad ground somewhere, or the wiper motor itself has a problem?

Also, the high beams don't work properly on the new switch. Pushing it forward to the high-on position doesn't work, and they only turn on when you pull the switch halfway back, then shut off if you pull it further. Is there a way to rebend the connectors to fix that, or is the switch no good? It's brand new but he bought it and I don't have a receipt. I'm not putting the old switch back incase it's bad and shorts something out. It feels pretty worn anyways.

 

[adsm08]

I would suspect the wiper motor having some internal short causing a feedback loop.

When running on high the wiper motor actually produces 18V just from it's own motion. I would suspect that the low speed produces just enough power to keep the motor running on it's own. Just a guess though.


As for your lighting issues.... sounds like another crossed circuit.

 

[JohnW]

I would suspect the wiper motor having some internal short causing a feedback loop.

When running on high the wiper motor actually produces 18V just from it's own motion. I would suspect that the low speed produces just enough power to keep the motor running on it's own. Just a guess though.


As for your lighting issues.... sounds like another crossed circuit.

He said he replaced the wiper motor but it was a used one so it may be bad too. I guess the next step is to find another one.

Could a short in the wiper motor damage the GEM?

And the high beam issue just started when I put in the new MFS, they worked fine with the old switch. I'm pretty sure it's a physical issue with the switch.

Edit: Directionals don't cancel now either. The brand new switch is junk, too bad I don't have a receipt for it. I'll have to look up the wiring diagram so I can test the old one.