Theme of the week: electrical issues that I can't figure out

[jeepmag]

For any GBBS fans out there, the theme of the week is electrical problems in my garage (for my LX470, my TJ,).

I am stumped on this one. Symptoms started like this: Initially, one fog light went out, and a bulb replacement did not solve the issue (this was 4-6 months ago). Then about 1 month ago, both fog lights became non-responsive and the toggle switch would not light up indicating they were on (this resolved itself the following night, but the symptoms returned 1 week ago). The about a week ago, I lost all illumination on my dash and center console (though the individual dash lights such as turn signals, shift indicator, seatbelt light, and parking brake work just fine). Radio and speakers work just fine, interior dome light operates normally, and the rear wiper/defroster switches work just fine (but they won't light up when I turn on my lights). ALSO, it turns out my brake and tail lights are out. However, hazards and turn signals operate just fine on the rear. I am not sure if my reverse lights operate.

So I did some digging, and I landed on Fuse #3 in the engine bay as the likely source as all interior fuses behind the glove box were checked out and determined to be functional. However, Fuse #3 looked undamaged, and even with a replacement fuse my symptoms did not resolve. Lights are still out, I have no tail lights or brake lights, dash problem remains.

I am at a loss. I have read up that maybe this could be the headlight switch, or an issue with a shorted wire in the rear(?). I do have some damage on the rear driver-side corner from an accident two years ago that did impact the tail light.

Does anyone have any ideas on what could be causing this? One thing? Multiple things? I'm at a loss at this point!

 

[Chris]

Yeah, if I had to guess you've got a shorted wire or a bad ground somewhere. The fun part will be tracking it down.

 

[ColoJeep]

For any GBBS fans out there, the theme of the week is electrical problems in my garage (for my LX470, my TJ,).

I am stumped on this one. Symptoms started like this: Initially, one fog light went out, and a bulb replacement did not solve the issue (this was 4-6 months ago). Then about 1 month ago, both fog lights became non-responsive and the toggle switch would not light up indicating they were on (this resolved itself the following night, but the symptoms returned 1 week ago). The about a week ago, I lost all illumination on my dash and center console (though the individual dash lights such as turn signals, shift indicator, seatbelt light, and parking brake work just fine). Radio and speakers work just fine, interior dome light operates normally, and the rear wiper/defroster switches work just fine (but they won't light up when I turn on my lights). ALSO, it turns out my brake and tail lights are out. However, hazards and turn signals operate just fine on the rear. I am not sure if my reverse lights operate.

So I did some digging, and I landed on Fuse #3 in the engine bay as the likely source as all interior fuses behind the glove box were checked out and determined to be functional. However, Fuse #3 looked undamaged, and even with a replacement fuse my symptoms did not resolve. Lights are still out, I have no tail lights or brake lights, dash problem remains.

I am at a loss. I have read up that maybe this could be the headlight switch, or an issue with a shorted wire in the rear(?). I do have some damage on the rear driver-side corner from an accident two years ago that did impact the tail light.

Does anyone have any ideas on what could be causing this? One thing? Multiple things? I'm at a loss at this point!

The multi function switches are not without faults . Look for ground and short issues in the wiring , then " ring out " where you have and don't have voltage in the circuit. With the other issues you mentioned it's likely a ground , but the switch is very suspect in my opinion.

 

[B1Toad]

Since the OP has a 2001 I believe the fog lights have a dash rocker switch and are not part of the MFS? To me the dash pullout light switch is highly suspect as the dash lights go through that switch, and the fig lights maybe but not 100% sure on that..

Here's what mine looked like after I took it apart. I had a really hard time locating an OEM and I'll bet they're now all gone.

 

[jeepmag]

Yeah, if I had to guess you've got a shorted wire or a bad ground somewhere. The fun part will be tracking it down.

I am going to replace the headlight switch first and pray I don't have to engage in a lost weekend

 

[Chris]

I am going to replace the headlight switch first and pray I don't have to engage in a lost weekend

That's where I'd start!

 

[jeepmag]

Since the OP has a 2001 I believe the fog lights have a dash rocker switch and are not part of the MFS? To me the dash pullout light switch is highly suspect as the dash lights go through that switch, and the fig lights maybe but not 100% sure on that..

Here's what mine looked like after I took it apart. I had a really hard time locating an OEM and I'll bet they're now all gone.

View attachment 658569View attachment 658571View attachment 658572View attachment 658573

Well, once this snow lets up this is going to be my next project

 

[Irun]

Given your location, start with the easiest. There are two grounds, one by each headlight, that I'd remove the bolts and clean everything up. These two grounds, along with the firewall, can do strange things to the lighting. I'd also be checking the wiring at the headlight connectors. Those, when corroded, will also cause downstream lighting issues. The grounds are easy and cheap to check, before spending money on a new switch.

 

[jeepmag]

Given your location, start with the easiest. There are two grounds, one by each headlight, that I'd remove the bolts and clean everything up. These two grounds, along with the firewall, can do strange things to the lighting. I'd also be checking the wiring at the headlight connectors. Those, when corroded, will also cause downstream lighting issues. The grounds are easy and cheap to check, before spending money on a new switch.

Assuming a headlight switch is not the answer, I do have some damage on my Jeep to the driver's side rear corner, impacting the rear driver's-side taillight (that rear corner struck a guardrail at about 40mph). Is there any wiring back there that could be causing this? Because I am considering starting there.

 

[Irun]

Assuming a headlight switch is not the answer, I do have some damage on my Jeep to the driver's side rear corner, impacting the rear driver's-side taillight (that rear corner struck a guardrail at about 40mph). Is there any wiring back there that could be causing this? Because I am considering starting there.

There are grounds there also. The front grounds are easier to check for corrosion.

 

[B1Toad]

If you go to the resources section you can download your factory service manual. Then go to the wiring section which is W-8 I believe and find the diagram for front lighting which will show you how the circuits run for all your front lighting. Write down the ground point numbers, then go to the component and ground location charts and look them up. It will tell you where they are located and it will say which page of the picture drawings they are on, then go to the correct picture page and locate them.
All this from the comfort of your PC while the snow is falling outside.

 

[jeepmag]

Since the OP has a 2001 I believe the fog lights have a dash rocker switch and are not part of the MFS? To me the dash pullout light switch is highly suspect as the dash lights go through that switch, and the fig lights maybe but not 100% sure on that..

Here's what mine looked like after I took it apart. I had a really hard time locating an OEM and I'll bet they're now all gone.

View attachment 658569View attachment 658571View attachment 658572View attachment 658573

Sadly my MFS looked like it was in good shape. I went ahead and replaced it anyways, but there has been no change (except now the fuel needle jumps a bit each time I turn on the dome light). Time to watch football and read the factory service manual.