Factory lighting issues, please help.

[OctaviousMonk]

I have a 2005 Wrangler Rocky Mountain Edition that started life as an X. The problem as it stands right now is that when the fog lights are turned on the passenger fog light does not light and the front and side driving/turn signals shut off. The corresponding left turn arrow on the center console also lights and remains lit. When I unplug the passenger fog light from the harness at the fender, regardless of the fog switch being turned on or off the same two lights shut off also, which is odd. When I disconnect the drivers side fog light the corresponding two lights do not shut off. Removing the fuse to the fogs does not affect the passenger side driving/turn lights either.
Sequence of events from purchase of the Jeep are as follow:
1: fog light fuse was blown and once replaced the fogs stay on continuously.
2: I repaired the MFSwitch and fog lights turn off when switched off.
3: I discover this issue and assume it’s the switch again, but it continues to happen even after I switched out the entire switch and relay with a known functioning one from my other TJ.

I know something must be very wrong with the wiring on that side but can’t figure it out at all. It just doesn’t make sense that the fog is tied into the other lights in any way shape or form.
Thanks for any help you can offer.

 

[Bill Clark]

I had a similar problem and replaced the MFS. Now I need a new one again or watch U Tube and fix it


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[OctaviousMonk]

I’d agree but I put in a known good MFS from my other TJ and it didn’t fix the issue. I also tested the questionable MFS on my other Jeep and it worked fine then.

 

[jgaz]

Have you checked all the ground connections? Using the electrical section of the service manual should tell you where they are all located.

I’d start with the ground connections only because the turn signal indicator lighting up seems to point in that direction. That kind of problem is usually caused by a backfeed in the circuit.

Do you have access to a factory service manual?

 

[OctaviousMonk]

I can try and hunt one down. I’m sure I can google one

 

[jgaz]

Start here
https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/

Open this, go to section 8w, and start with “ground distribution”.

8w-91-1 should be more help with the physical locations of the ground connections. Start with your fog lights, side marker lamps, turn signals, and front running lamps.

Has the Vehicle ever been in an accident? Could be a ground wire wasn’t reconnected during the repair.

 

[OctaviousMonk]

Problem solved. It ended up being a weak ground where the simple headlight ground split off to supply the fog light and both parking/turn signals. I spliced in an extra heavier gauge ground wire to supply those light and tied it back into the headlight ground feed just because. Now everything is working well together. It’s very odd that the corrosion made it that far down into the ground wire run and didn’t compromise the headlight which is what the run hits first. Oh well thank you very much for the help.

 

[jgaz]

Glad you figured it out. You’d done the hard work by eliminating the MFS.
I figured it was ground issue that’s why I sent that link.

Thanks for letting us know what the problem was.

 

[Bill Clark]

Problem solved. It ended up being a weak ground where the simple headlight ground split off to supply the fog light and both parking/turn signals. I spliced in an extra heavier gauge ground wire to supply those light and tied it back into the headlight ground feed just because. Now everything is working well together. It’s very odd that the corrosion made it that far down into the ground wire run and didn’t compromise the headlight which is what the run hits first. Oh well thank you very much for the help.

Thanks. I appreciate that



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