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2002 F250 with 7.3 electrical problem

Dickjr. ยท 2018-02-28 16:20

My service truck has an electrical problem of some sort. When you turn it off and open the door the radio keeps playing. No other functions work. I checked the door switch it seems ok. I have read there are 2 different modules that can cause this. I was hoping to get a little insight here before I take it to a shop. The other day I noticed it was making a buzzing noise , opened the hood and the windshield washer pump was pulsing. I wouldn't mind taking it to a shop if I knew they wouldn't start changing parts and run a big bill up over a 100$ module. Any pointers would be greatly appreciated.

Replies16
  1. #1Delmer2018-02-28 16:28

    I don't know anything about those modules, but my first guess is a bad ground somewhere. Two different malfunctions, one caused by another third function operating, that sounds like a ground wire backfeeding to me. UNLESS you can find better advice specific to that ford module, that's what I'd check first, follow your harness and examine every little black wire that comes out to a ground screw, the chassis to engine ground, and the negative battery cables.

  2. #2Wytruckwrench2018-02-28 17:31

    I have had a lot of those where the GEM module starts doing weird stuff. Caused by the windshield leaking on to the GEM module.

  3. #3JNB2018-02-28 18:35

    This was a problem on my oldie but goodie '99. The seal looked fine, but was leaking.

  4. #4DARO2018-02-28 21:27

    And if i remebering rite... the windshild washer and wiper are controled by the gem module? I could be off its been a few years.

  5. #5Dickjr.2018-02-28 21:29

    I have read about the gem module , from what I can tell its on the back of the fuse block. You can hear a clicking noise under the dash. This truck has served me well with only 165k miles on it. But these things are aggravating to no end.

  6. #6Dickjr.2018-02-28 22:44

    I went out and took a look at it again. Its been raining here 5 days a week for a month and sure enough there is moisture by the parking brake peddle. I removed the fuse panel cover and it smelled of burnt electrical. Looked on ebay and found a GEM for 145$ with 6 month warranty. I'll roll the dice on this one , the guy I called that does auto electronics for a living said he had no idea and would have to tear into it. Which to me means grab your ***. These forums continue to be the most helpful.

  7. #7DARO2018-03-01 10:23

    I think the gem controls the power windows also?

  8. #8kenh2018-03-01 12:20

    Per 2001 Manual, wipers, windows controlled by GEM. Windows also go through Central Junction Box. can look up various circuits but manual has no pin out of GEM,

  9. #9PJ The Kid2018-03-01 12:52
  10. #10dieseldog5.92018-03-04 19:01

    I have a fuse box on my desk from an F550 that the hole in the roof for CB or strobe light leaked down the A-pillar and soaked the panel and module corroding the whole unit, nice thing about these trucks ther were a lot of them out there so used parts are available. Also be paying attention when looking up wiring schematics, each year was very different even with the same engine combination.

  11. #11DMiller2018-03-11 17:04

    Sounds like a bad module ground or radio ground when the dome lamp grounding switch engages it backfeeds to turn the radio on.

  12. #12Edward Porter2018-03-11 22:45

    Had a 99 Expedition . Water leaking on fuse box causing shorts and back feeding electric. Found the leak after fiddling for hours and sealed it with silicone and dum dum. Cleaned the fuse panel and dialectic greased the connections. Finally works after many years hassle All kinds of strange happenings till it was fixed right.

  13. #13murfdog2018-03-12 09:14

    I parted out my '02 7.3, Let me know if I can help out with anything. I don't have the ECM, gave that to a guy in need

  14. #14Bls repair2018-03-16 06:21

    If you want to fix it cheap turn off the radio off manually.

  15. #15Dickjr.2018-03-16 19:55

    I removed the cover and the fuse panel cover. The fuse panel cover had a little water in it. I started the truck turned the heat up , let the windows down about 1" each. So far it seems ok. Got to stop that leak. Its either the windshield or the safety light that I broke off. Thanks for the replies. I wonder what a shop would have charged me for this.

  16. #16DMiller2018-03-16 21:15

    My '99 has not developed any cab leaks as yet and YES I am knocking on all wooden surfaces including my head right now. Get it located and fixed before it eats it up worse.