3rd brake light (CHMSL) no power

[spoon359]

2018 JL Wrangler Sahara

The light is good but has no power going to it. I’ve checked wires and connections back to where they go into interior wall inside cab by right rear tailgate and wires are good. Other tail lights, turn signal, brake lights all work perfectly. Can’t find a dedicated fuse for just the 3rd brake light. Any ideas will be greatly appreciated.

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[Flip]

2018 JL Wrangler Sahara

The light is good but has no power going to it. I’ve checked wires and connections back to where they go into interior wall inside cab by right rear tailgate and wires are good. Other tail lights, turn signal, brake lights all work perfectly. Can’t find a dedicated fuse for just the 3rd brake light. Any ideas will be greatly appreciated.

Did you use a multi-meter to confirm there is no power to the 3rd brake light?

 

[spoon359]

Did you use a multi-meter to confirm there is no power to the 3rd brake light?

Yes. First thing I did.

 

[Flip]

I'm wondering if there is a separate fuse just for the 3rd brake light?

This is the tool I use; I would start from the 3rd brake light and work my way back. Find out where that wire has lost power. Also look to see if you can find the ground for the 3rd brake light.

 

[Heimkehr]

The light is good but has no power going to it.

Prior to observing that the CHMSL wasn't illuminating, were you doing any work on the rear of the vehicle that would've required unplugging the connector on the underside of the light? The pins are small and fragile, and thus easily bent if not taking proper care when buttoning things back up.

Otherwise, manually trace the wire(s) as suggested in the preceding post.

 

[spoon359]

Prior to observing that the CHMSL wasn't illuminating, were you doing any work on the rear of the vehicle that would've required unplugging the connector on the underside of the light? The pins are small and fragile, and thus easily bent if not taking proper care when buttoning things back up.

Otherwise, manually trace the wire(s) as suggested in the preceding post.

I’ve traced them to where the wires go in rear right wall. So I’ve gone as far as I can without tearing the interior out of it. I haven’t taken anything apart until I pulled connections on wires apart to check for power. The pins looked good

 

[Heimkehr]

The pins looked good

Mm. Ok. If the light has been tested functional in isolation, then continued wiring tracing seems to be the next logical step.

 

[Flip]

I’ve traced them to where the wires go in rear right wall. So I’ve gone as far as I can without tearing the interior out of it. I haven’t taken anything apart until I pulled connections on wires apart to check for power. The pins looked good

Tracing wires can be a pita! I can't speak for my new wrangler yet but I'm usually pretty good at it. You have to really get into it, trace that little rascal down, think of the feeling of accomplishment, Victory will be yours! Time & patients, you can do it! ?

 

[Heimkehr]

Tracing wires can be a pita!

Absolutely, which is why I was asking questions before recommending that the OP continue doing so. It's not advice that I give lightly; I've owned three British cars and have paid my dues in that regard.

 

[19 JLUR Bright Whit3]

Pardon my candidness.

Just wondering how did you test the bulb was good?
Also, someone needs to step on the brakes for you to test if there is power going to the third brake light.

 

[Dyolfknip74]

There is a fault circuit. I bet you have a short somewhere. It won't trip a fuse.
I had something similar when I relocated plate and ran plate light off of right tail light. I had twisted new plate lightnLED and it was shorting out causing the running light portion of my tail light to not work.

 

[19 JLUR Bright Whit3]

There is a fault circuit. I bet you have a short somewhere. It won't trip a fuse.
I had something similar when I relocated plate and ran plate light off of right tail light. I had twisted new plate lightnLED and it was shorting out causing the running light portion of my tail light to not work.

OP said he never touched any of the wiring. If its not a corroded ground, it has to be the bulb. Just my $.02.

 

[Dyolfknip74]

OP said he never touched any of the wiring. If its not a corroded ground, it has to be the bulb. Just my $.02.

You can have a short without touching wiring.
I have LED package, not sure if the middle light is LED on all models but if it is, a faulty LED is possible but doubtful. OP really needs to confirm it.

 

[Flip]

OP said 'The light is good but has no power going to it."

He said he checked the wire connections at the 3rd brake light with a multi-meter and there is no power.

I'm not familiar with a fault circuit. I would definitely check that, where is it located?

 

[19 JLUR Bright Whit3]

OP said 'The light is good but has no power going to it."

He said he checked the wire connections at the 3rd brake light with a multi-meter and there is no power.

I'm not familiar with a fault circuit. I would definitely check that, where is it located?

Yes. I'm tracking what the OP posted, but.....how does he know the bulb is "good" and "no power is getting to it" There is no power going to my third brake light until I step on the brake and bulbs may look good unless you run an isolated power source to it.
Again. It's just my take that grounds and bulbs go bad before wire harnesses if nothing has be disturbed. I was just trying to save the OP from ripping out his interior. I'll stop then.

Best of luck to the OP.

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