Brake lights not working when headlights are on after taillight guard install

Tank97

Tank97

Member
Joined
Apr 11, 2018
Messages
61
Location
Branson MO
Hello everyone, I bought my 97 TJ last fall and have slowly been getting it back into good running condition. I have fixed almost everything other than one mysterious issue that I can't find info on. So I am finally ready to start customizing my TJ on of the first mods I did was put break light guards on. simple 3 screws on each side and your done. 10 minute job. But ever sense I put on those guards my break lights have been supper wacky. for starters. When I flip my blinker on it flashes really fast and both the intended blinker side and my third break light flash. This happens for both my right and left blinkers. Secondly whenever my headlights are on all three light in the back blink whenever I turn on either of my blinkers. Lastly, whenever my headlights are on, if I push on the break peddle the third break light lights up like normal but the other two go out. I should also include the fact that the previous owner added a trailer light harness, so there are quite a few splices behind my driver side brake light.

I'm sure Its something simple but I'm just not quite mechanically inclined enough yet to figure this out. Thank you in advance for all the help
 
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Those brake light guards are the issue. They are notorious for causing the exact issue you described, which is why I always encourage people not to use them, or throw them away (they also cause rust).

The issue is that the taillights on the TJ are grounded by the screws that hold them to the body. Bu sandwiching them between that powder coated plate / guard, you used the ground connection to be interrupted, hence all the weird issues you're having.

Your best bet is to get rid of those taillight guards, honestly. It will fix all your issues.
 
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First of all, thank you so much for the response and info, this forum has been a life saver in many situations.

Well, that's a bummer. I don't want to get rid of the guards, they were a gift from my girlfriend so throwing them out would probably result in some hurt feelings. is there not another way to ground them, can I sand off the polish? or do you honestly think that keeping them will cause more issues?
 
Taillight guards are notorious for causing electrical grounding problems for the rear taillights which causes the taillights to have problems or stop working entirely.

Show her this thread and she'll understand why it'd be a good idea to return them for something else. :)
 
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Okay, so I recreated the ground by putting a longer/larger bolt through the body and put a nut on the bolt. this fixed the problem, At least for now. I will still let my girlfriend know about the issue in case my fix isn't long term.
Thank you very much for the input! I look forward to learning more and more about my jeep through the resources on this forum.
Have a great day!
 
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I have tail light guards on and have never had a grounding issue. I attach my ground on the bolt but on the inside of the tub, not on the outside so its touching anything to do with the guard itself. No interference.
 
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