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Hey everyone, I took my truck to get a new transmission put in and on the way back home I lost power to several of the body control functions. I have lost the horn, dome light, windshield wipers and spay, door locks and windows. I have replaced the gem module and still nothing. I have also replaced the ignition switch and nothing. I have tested all fuses and relays both under the dash and under the hood. I have also checked the window motors with straight 12v and they work as well. What is weird is when you press the window switch the relay under the dash almost makes a whining noise. Also when the door is open sometimes the dome light will click on and off with the relay. Also only when I turn the key backwards the accessory the windshield wipers will work sometimes. Do I have a short in the fuse box? Or potentially a wiring issues elsewhere? I am at a roadblock and do not know what to test next. Any help would be appreciated.
I would check for a loose or bad ground. Starting with anything they could have touched during the transmission replacement.
Seems like @Sous has talked about a common issue with a ground near the brake reservoir area but I can’t remember which model years or exactly where at the moment.
I would check for a loose or bad ground. Starting with anything they could have touched during the transmission replacement.
Seems like @Sous has talked about a common issue with a ground near the brake reservoir area but I can’t remember which model years or exactly where at the moment.
Thanks for the info! I will look into his post history. Curious if anyone knows exactly where the grounds would be located? I have done a basic overlook for the grounds but did not have much success in locating but a few.
Jason is right, there is a major system ground (G100) near the driver fender and firewall corner that you could check.
The GEM would have been my primary target as well based on the trouble description. Do you have any stored or active codes in the PCM? There are a couple dozen GEM related codes.
Without looking at the list in the Ford Service Manual, I believe those are all accessories controlled by the GEM. If I have time today, I will take a look. I am not sure where the ground point for the GEM is at, but i will look for that as well.
In the meantime, there are some documents and links in the 7.3L PSD Tech Folder that may interest you, I have linked them below.
Thanks for the info! I will look into his post history. Curious if anyone knows exactly where the grounds would be located? I have done a basic overlook for the grounds but did not have much success in locating but a few.
I tagged Sous so knew he’d be along soon to clear up the details (thanks Sous!)
It seems too coincidental that this started during the trip home from the transmission work. That’s why I’m curious of looking into anything related to that work.
It seems like there may be a ground on one of the bell housing bolts. Near or on the dipstick tube bracket, but I may just be thinking of that bracket itself.
How about any harness wires that could have been pulled (forgot to disconnect during removal) or crushed when they put it back in.
Have you talked to the shop yet? I’d want to know if they had anything unusual happen during the work. And what connectors they may have touched. Not to accuse them of wrongdoing, just as a knowledge thing.
CJoyner12, reading the post from Jason below, I would start by looking for the ground connection identified as G300 in my previous post. It appears to be near the bell housing as Jason described below...
Originally Posted by RacinJasonWV
I tagged Sous so knew he’d be along soon to clear up the details (thanks Sous!)
It seems too coincidental that this started during the trip home from the transmission work. That’s why I’m curious of looking into anything related to that work.
It seems like there may be a ground on one of the bell housing bolts. Near or on the dipstick tube bracket, but I may just be thinking of that bracket itself.
How about any harness wires that could have been pulled (forgot to disconnect during removal) or crushed when they put it back in.
Have you talked to the shop yet? I’d want to know if they had anything unusual happen during the work. And what connectors they may have touched. Not to accuse them of wrongdoing, just as a knowledge thing.
Your welcome Jason and I am glad to help in anyway I am able. I hope the issue is resolved soon for CJoyner12 and they can continue on with more important life happenings.
I have checked all the grounds and they are all in good shape. I believe I have narrowed it down to possibly a shorted fuse box under the dash. Sometimes you can turn the key to accessory and the window switches will make the wiper pump come on. Sometimes the window switches will make the really make a high pitch whine. Other times it will make the relays click really fast and the dome light will come on and off with the clicking of the relay. Could it be possible that something is Burnt up in the fuse box or relays that’s making it do all this sporadic stuff?
I have not noticed a leak nor any evidence of one. When I pulled the fuse box the first time there was one pin on one of the connectors for the fuse box that had a small bit of corrosion but nothing that would cause major issues. This afternoon I did take time to test the relay sockets on the fuse panel under the dash with a multimeter and the relay number 4 which controls the windows is reading a mix of voltage on almost all the pins so I assume it is shorted out. Which would explain why the window buttons control random things when hit. I’m going to order a fuse box and go from there unless they can be repaired?
@Y2KW57 , I would like to nominate the post linked by kbeefy to be included in the 7.3L PSD Tech Folder. I realize the Excursion is a 5.4L gasoline engine, but the method of cleaning and attention to detail by 2112RUSH are worth including in the Tech Folder, in my humble opinion. At the very least it is worth a nomination.
That's strange... our tech folder folder was originally based on the Excursion tech folder, and that thread was in that tech folder, but for some reason it was not in ours. It is now.
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