Tail & reverse lights (ghost lights!)

[Navyfam00]

Good day to all! I’ve got an interesting one that has me, as well as an auto electric shop absolutely perplexed. Here’s the deal: 2004 Ford Expedition Eddie Bauer 4x4 5.4, has the most strange
issue where the tail lamps and OR reverse lamps begin to glow on and off intermittently when the vehicle is off and parked in the garage. Yep, no rhyme or reason why one will glow when or vs the other, but that’s been going on for 7 months, and I haven’t been able to fix it. The auto electric shop in town swore that it was the fuse block down in the passenger side kick panel, which i’ve since replaced- but that’s doesn’t appear to have been the culprit, as the issue returned since the replacement (although, is was hopeful, as I hadn’t seen the issue for several weeks after the replacement— but the fault did in fact return). The lights will dim at random, sometimes brighter more on one side than the other, and it makes no sense to me at all. The car is a good car, but I can’t dump thousands into it, and it’s really beginning to make my wife and I feel like there’s no other option. A couple more possible hints — the aftermarket car stereo reverse camera kicks on intermittently while driving, presumably because is detecting a voltage in the camera trigger wire, which i neatly tied into the passenger side reverse lamp bulb assembly. This leads me to believe that even when the car is running, that there is/are stray voltages in the lighting circuits, which would
trigger the stereo head unit to believe the vehicle is in reverse.

Any help would be amazing— and i’d really really appreciate any advice. Thank you very much!!!

Respectfully,

Joe

 

[99WhiteC5Coupe]

Good day to all! I’ve got an interesting one that has me, as well as an auto electric shop absolutely perplexed. Here’s the deal: 2004 Ford Expedition Eddie Bauer 4x4 5.4, has the most strange
issue where the tail lamps and OR reverse lamps begin to glow on and off intermittently when the vehicle is off and parked in the garage. Yep, no rhyme or reason why one will glow when or vs the other, but that’s been going on for 7 months, and I haven’t been able to fix it. The auto electric shop in town swore that it was the fuse block down in the passenger side kick panel, which i’ve since replaced- but that’s doesn’t appear to have been the culprit, as the issue returned since the replacement (although, is was hopeful, as I hadn’t seen the issue for several weeks after the replacement— but the fault did in fact return). The lights will dim at random, sometimes brighter more on one side than the other, and it makes no sense to me at all. The car is a good car, but I can’t dump thousands into it, and it’s really beginning to make my wife and I feel like there’s no other option. A couple more possible hints — the aftermarket car stereo reverse camera kicks on intermittently while driving, presumably because is detecting a voltage in the camera trigger wire, which i neatly tied into the passenger side reverse lamp bulb assembly. This leads me to believe that even when the car is running, that there is/are stray voltages in the lighting circuits, which would
trigger the stereo head unit to believe the vehicle is in reverse.

Any help would be amazing— and i’d really really appreciate any advice. Thank you very much!!!

Respectfully,

Joe

Do you have all OEM bulbs in all the sockets (anywhere) - or have you installed any LED bulbs anywhere?

 

[BigOleFordFan]

Sounds like a voltage leak, or a phantom ground that exists in a place where it shouldn't be, like near a frame member, engine mount, support bracket, or some other mass of metal that's not supposed to be grounded..

 

[DieselMonk]

First step is to get a proper wiring diagram for your truck. You can purchase these for like $20 for a single VIN. May also be a chaffed wiring. The power gotta come from somewhere.

 

[Doug Reed]

No solutions offered but I too have had many mysterious electrical gremlins in my 04 NBX that have stumped the dealerships and shops. Side mirrors, radio, power seat, power locks etc. I use my expedition mostly as a tow pig and all I have to do is look at the price of replacement and I decide to put $ into it. It's getting new step bars today!

 

[EngineerMike]

Did you or a confederate install any "custom" trailer wiring that included a hot wire? If not that, I vote chafed wire, two wires have to be picking up voltage someplace.

 

[chuck s]

First suspect is someone installed LEDs in lieu of light bulbs.

-- Chuck