Speaking of Older F150s - The HuntingPA.com Outdoor Community
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post #1 of 1 (permalink) Old 02-06-2016, 07:41 AM Thread Starter
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Speaking of Older F150s

Has anyone that has/had a 2003(ish) F150 ever experience the electrical gremlins that seem to be caused by moisture in the GEM module?

This is driving me nuts!!

Through the problems I've had and reading enough on the F150 forums, I'm fairly certain that module getting wet is the cause. It seem that this module controls just about all of the electronics for the truck.

If you never experienced it, I'm telling you, it's wild! I come out to the truck at lunchtime one day and the door chime is going off, the radio is playing, and the dome lights are on. Or the windshield wipers will only come on or turn off if I'm in Park or Neutral. That took a little while to figure out, but not until after driving down the Autobahn in sunshine with the wipers going. Or when they wouldn't come on in a downpour. And the first thing that happened was the blower for the heat/ac staying on with the truck off and the key out. First noticed that one after the battery was drained...twice!

This has been going on for a couple of years, but only once or twice a year, and only after severe storms. Then it would dry up and everything was good. Now it's happening more frequently, and since I need to keep the truck a few more years I decided to do something.

I searched for the GEM module before, but only to find the were anywhere between $250 and $700, used and might not be the right one. Apparently they're programmable, depending on accessories, and if not done right could cause more problems.
I just found one with exact P/N as mine on eBay for $89, so I ordered it. If it don't work, at least I'm not out too much.

I also think I found the source of the leak. I've opened the door many times to water puddles on the driver's side floor mat. In the forums they say it's a common problem with windshields in these trucks leaking. But I don't think that's it. The foam strip under the windshield, where it beds, is soaked right now. Which should be normal, but with the driver's door open I can see space in between some body panels right under that foam. I'll have to pull the plastic strip under the windshield, where the wipers are and seal that all up. I hope that's it!

I've gotten used to dealing with it. When it's dry and acting normal it's fine. But once there's any indication it might act up, I disconnect the battery every time I park. Which gets to be a pain after a while.

Anyway, I hope I'm on track to fix it. Anyone else ever deal with this?

Shoot straight

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