Ok people - I need some advice. My truck has had trouble with the wipers since I got it a few months ago. When I got it, the wipers worked fine, but then started acting up until they only sort of worked on high if they felt like it. I followed the advice of a trusted friend and replaced the switch and everything seemed fine again for a little while. Now they are back to sort of working on high. This time I swapped out the motor with no change. I figure the switch is toast again, but hesitate to go out and buy another one without knowing what's going on here.

My best guess is (a) that the old motor may have been on the way out and drew enough current to burn out the switch, or (b) there is a relay out somewhere driving me crazy.

Any words of wisdom before they send me off to the funny farm?

 

Fuse good, ground, switch, motor and maybe a relay or 2 to work with right? My other brand X wiper issue ended up being not the $ multi function combo t/s switch or the $ motor, just a good ground issue or lack there of it.

 

Thanks Rich.

I'll try making ground jumpers for both the motor and the switch and see what happens.

 

Have you tried the infamous "wiper no cost fix" yet? If not, then preview the "Read First" thread for our trucks at the beginning of the forum. I would post the link but I don't know how to copy and paste a link from the forum. I did it with my truck with excellent results.

 

I've read through that thread and it doesn't seem to be the issue I am having. Thanks for the information though.

 

my issues seemed more like yours than the ones in that thread, but i had tried everything else and i didnt have anywhere else to turn so i went though the procedure as outlined ... wiper problems gone. it doesnt take but a few minutes at any rate and doesnt cost a penny.

 

Mine only refuse to work when it rains......

I too will check the a fore mentioned thread....

 

Well, I think I've narrowed it down to an intermittent wiper control module failure. I'm hoping that I can figure out what's wrong with it and make some repairs. This part is no longer available new, no I'll either have to fix it or find a functioning one in the junkyard somewhere.

One question, could I remove the module and plug a 2 speed switch into the harness and have two speed wipers?

 

There was a recent thread around here somewhere about this issue. Apparently the whack of the parking brake release causes shocks to the module which is mounted to the parking brake assembly. These shocks cause solder joints to break loose causing failures. Some indicated that they had successfully resoldered the joints and gotten it working again for a little while. One posture resoldered it, wrapped it foam, and zipped tied it up to something else under the dash. His fix was still working many years later.

Might be worth looking into the module.

 

I just removed the module and installed a 2 speed switch - wipers now wipe. Unfortunately I somehow or another I've caused a short in the headlight circuit and blew that fusible link. So far I've disconnected the headlight switch and still have a short so tomorrow I'll drop the fuse box and see what ham-handed stunt I've done now. Once I figure the short out, then I'll fix the link.

Never a dull moment on this thing...

 

Well - I think I found the source of the short. Apparently when I plugged the light switch back in, the main power wire popped out and was shorting against the fuse box bracket. I thought I had pulled it clear when I initially disconnected the switch. I've inspected the area around the harness and located the point it shorted out. At the moment, I no longer have continuity between the the feed wire and ground.

I'm going to carefully put everything back together and secure that wire so it stays put. If it goes back together without shorting back out, I'll go ahead and replace the fusible link.

Has anyone had any luck putting in a heavy duty weather proof fuse instead of a link? I was thinking it may be easier to replace a fuse rather than a link if I'm still having trouble.

I'm going to careful

 

I did that on my truck after much thinking and discussion with others here. One thing that I found is that Ford seems to run the circuits through the fusible links on the ragged edge of the ratings that I'm used to dealing with in the marine world.

One thing that is a _must_ is you need a 3G alternator. With a 2G alternator the charge circuit is run through the same lead as the voltage sense wire. That means you need to fuse it at 70 amps to handle peak charge loads. (60 amp alternator plus a little cushion) In my world the max amperage rating for 10 gauge wire in an engine space is 51 amps. The 3G alternator separates the voltage sense and charge output functions into separate wires.

I used a combo fuse and relay unit Sealed Mini Fuse & ISO 280 Mini Relay Panel with Bussed Inputs which provides plenty of fuses as well as the ability to add relays for lights and what not.

 

I'm only talking about the line that powers the headlight circuit, not the entire charge circuit so I'm pretty sure I can get away with a lower amperage than that.

 

I think the fusible links are used because they blow slower than a fuse. If you replace them with a fuse you could have it blowing because the circuit pulled x amps for a split second where a fusible link would not have blown.

 

Forgot all about the slow blow aspect of a fusible link. Thanks!