No rear lights?

T

Tnpete

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Joined
Sep 24, 2024
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Location
West Tn
2009 Jeep Wrangler JKU
Pulling the boat Friday. Noticed I had a air bag light, Seat belt Light on. Also no interior light, no tail lights, no rear turn lights, no brake lights. Even the Third brake light is not working?
What I have done so far. Checked every ground I could find. Right front ground by the power steering reservoir. Fire wall down to the block behind the heat shield. Both under the seats. Read that there was 2 under the console. But have not found those yet.
With my test probe, I can get ground at the taillight. Also if I back feed power to the trailer plug. I get the rear tail lights to work. But turn signals are still just working on front. Plus the hyper blinking as the back is not working.

Is there a ground just for the all the rear lights? IF so where would it be? Also could it be the light switch itself? Even with the third brake light not working?

I don't like electric work. But would rather stumble though then pay someone else to work on my jeep.
 
Tnpete said:
Yes horn works. Hazard lights in front only. Back there's nothing.
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OK. I was thinking clockspring but if your horn works that rules out that idea. Is your trailer plug on the Jeep side a 4 or 7 way? Also, do you get any turn signal or breaks on the plug?
 
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JeepJeezy said:
OK. I was thinking clockspring but if your horn works that rules out that idea. Is your trailer plug on the Jeep side a 4 or 7 way? Also, do you get any turn signal or breaks on the plug?
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Trailer plugs a 4 way. Nothing on it dead also. Used the kit to add the trailer plug that plugs into the drivers side tail light plug.
 
Do you still have and does the center brake light work?

On mine, I lost the rear corner lights, but the center still worked.
This happened after I jacked around with settings in JSCAN for DTRL and LED fog lamp settings.

I could not find a fuse for the brake lights then, and when I reset the system configuration back to factory on JSCAN, it magically made the brake lights work as intended.

I didn't mess with the DTRL & Fog Lamp settings again and it's never happened since.

Even if you didn't make any changes, it might be a good idea to look for codes, and maybe even reset things if you have that option.
 
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Center or third brake lights not working. Jscan did show I think it was current high on Right tail light. That was about the only code it showed for any of this. Might see if I can find the reset button and try it.

Trailer plug has been installed for a year.

Happened before dunking the boat. The airbag and seat belt lights showed up, when I stopped to pick my son up.

Only other thing I can think of. WE had a big rain a few days before. Pass seat was wet after that. That might have something to do with the air and seat belt lights. But not sure on the dead rear end lights.
 
I have heard that light switch can cause part of this issue. But being the front works, but not the back? Also third brake light should not be effected by the light switch?
 
Tnpete said:
I have heard that light switch can cause part of this issue. But being the front works, but not the back? Also third brake light should not be effected by the light switch?
Click to expand...

Have you checked the wiring harness from the tail lights to wherever they go into the body for chewed spots or broken wires? Squirrels, rats and mice like chewing wires.
 
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BLACKJKU said:
Have you checked the wiring harness from the tail lights to wherever they go into the body for chewed spots or broken wires? Squirrels, rats and mice like chewing wires.
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Yes followed it all the way up front. Can't find any spot that looks eaten on. Still thinking ground, but for the life of me can't find that ground. Had to be one for just though lights. Also southern jeep, no rust. So far have not found a wire growing green stuff yet.
 
There are ground studs on the insides of the fenders in the engine compartment and inside at the footwells, have you cleaned them? It's hard telling how Chrysler did all there grounds.
 
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1o1Proof said:
So all lights worked up to the point of hooking the trailer up?
Click to expand...

That's where I'm at.
While the connector is a match for the 4-pin on the Jeep, there is no telling how the trailer wiring was done, so they may have used an alternate pin layout on the trailer.
Do the lights work again if the trailer is disconnected?

I would use an external power source to confirm operation of the trailer wiring and pin-out at the connector.
I would also confirm the outputs at the Jeep connector are as expected.
 
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