Hello all,

I have a 1997 F150 XLT 4x4 that has developed some electrical problems. I've been told they can all be caused by a Computer Control Module but I need to narrow down just which one it is, where to find it, and if anyone knows...how much will it cost me to either replace it, or take it out to have it fixed. I took it to a local Ford dealership but they said it would cost close to $1000 to repair, including replacing the module and the labor.

These symptoms don't happen all the time, in fact I never know from one time to the next when I drive the truck if everything will work or not. But the exact functions that are affected are the windshield wipers, the power windows, the inside dome light, and the outside rear truck bed light, on top of the cab. These seem to be the only things that "go off" periodically. Sometimes these functions will not be working when I first start the truck of a morning, but sometimes when I'm driving down the road they will suddenly just come on, but I don't know what triggers the failure or what reactivates them.

Has anyone had any experience with this problem, and can anyone tell me which module controls these functions and what it would take to repair it? Thanks!

 

The good news...None of those functions have to do w/ the Computer Control Module (ECU).

Do you always loose "all" the functions mentioned at the same time, or just "some" of them.

Sounds more like a shared ground connection.

 

Yes, all of these functions either work, or don't work, all at the same time. Just the other day, I was unlocking the door late at night, and when you pull on the door handle the inside light and the truck bed light will come on. This time they came on and then "boom", went right back off! When I opened the door the dome light didn't come on, and when I started the truck I tried the windshield wipers and they didn't work, and neither did the power windows. So whatever is causing this it happens suddenly, and will go away suddenly too. When this happens I will turn on the wipers and leave them on, and occasionally when I'm driving down the road they will start working and the power windows too. I never know when it's going to happen.

So if it's NOT a control module, what is it? This is what the Ford dealer told me it was.

Thanks!

 

It sounds like the problem has to do with connective integrity. The circuits most likely share a common ground. When the common ground is lost, all the circuits sharing the ground are lost.

 

I bet it is the GEM Module , after re reading your post jam POSITIVE. I had some of the same issues and changed the GEM Module which is located on top of the fuse box lower driver side. Dealer will want a grand to fix. First thing is check your windshield top seal. Water leaks are apparently common issue with 1997 thru 2003 F-150's . Checked mine and was leaking and GEM Module is directly below where water drips behind dash right on it. I put new glass and seal as well as removing rust and then bought a New GEM Module off eBay for under 250.00 replaced it and truck has never repeated an issue. Again I say dealers will want very close to a grand to replace it not counting windshield seal. But you do need to fix the water leak first, or you will be doing it again

 

I think you're right. A GEM module is a General Electronic Module. The OP was just using the wrong name in referring to it.

 

Thanks Willtransco! Did you do all the work yourself? Is it necessary to pull the dashboard to get to the module, or can it be done from underneath?

I did have a leak on the top windshield and used some RTV Sealant and ran a bead across the top to seal it. I wanted to try that first before going through the expense of replacing it and re-sealing it. It seems to have worked as far as the leak goes, but the module still goes on and off. I'll have the windshield replaced and sealed good before buying a new module. Hopefully keeping the moisture out will be enough. But if that doesn't work I'll check Ebay for a new module. You're right, my local dealer did want close to a Grand to fix it, and the price on their new modules was $750. Thanks everybody for your help!