# Trailer lights troubleshooting.. Need help tried everything



## JustJoe (Mar 20, 2014)

Hello all

Please help. I can not figure this out.. My tow vehicle is a 98 jeep cherokee XJ. My trailer has a tilt. I installed new pre wired non led lights and a new coupler. I used a T connector to tap into the jeeps wiring without splicing it. 

My lights stay on when the trailer is not hitched but as soon as I lift it and lock it to the ball they go out. 

I have cleaned the ball socket on the coupler, the tilt joint on the trailer, all the grounding points have been resanded with new bolts installed. 

I tried running a ground from the trailer to the jeep, I tapped into the lights and grounded the t connection to the jeep. I ran a temporary ground to all the lights and then to the ground on the trailer near the coupling but not to it. I even drove the trailer around the block a few times hoping it would work

I'm really stumped here.


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## huntinfool (Mar 20, 2014)

Usually on a tilt trailer the tilt joint doesn't support a sufficient ground. 
However it seems that you ran a ground from the jeep to each light and it still failed? 
Where do you have the T1 grounded? 
If you have a sufficient ground on the T1 and a ground run to each light and it goes out when the ball touches the coupler? 
When you say you ran a ground to each light, do you mean a wire from the T1 to each light with a wire or grounded each light to the trailer?
My initial suggestion is if you are not using the tilt function, take a wire and ground the tongue to the frame at the tilt joint. That should help establish a solid ground. Also if the trailer is all bolted together vs. welded, there may be some corrosion between each piece. A ground wire between the frame and the tail light bracket may be necessary. 
Can you take a picture of the trailer? 
I do this for a living, but need some more info to help.


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## lckstckn2smknbrls (Mar 20, 2014)

Have you tried hitching the trailer to a different tow vehicle or a different trailer to your Jeep?


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## JustJoe (Mar 21, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=345669#p345669 said:


> huntinfool » 20 Mar 2014, 21:34[/url]"]Usually on a tilt trailer the tilt joint doesn't support a sufficient ground.
> However it seems that you ran a ground from the jeep to each light and it still failed?
> 
> Where do you have the T1 grounded? About 6" from the T to a grounding point on the body in the truck
> ...


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## JustJoe (Mar 21, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=345675#p345675 said:


> lckstckn2smknbrls » 20 Mar 2014, 22:02[/url]"]Have you tried hitching the trailer to a different tow vehicle or a different trailer to your Jeep?


 Uhaul trailer worked fine with the jeep


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## huntinfool (Mar 21, 2014)

Looks like a mostly bolted together trailer. 
Make a jumper at the tilt joint. 
Also do you have a test light? Clamp the ground end to the bolt that mounts the light and then probe the running light. If you do not get power then you probably have a break in the ground. You can run a ground wire from the tongue to each light and that should correct your problem. Or you van make a jumper between each bolted on part. 

Hope this helps.


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## JustJoe (Mar 21, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=345700#p345700 said:


> huntinfool » 21 Mar 2014, 06:21[/url]"]Looks like a mostly bolted together trailer.
> Make a jumper at the tilt joint.
> Also do you have a test light? Clamp the ground end to the bolt that mounts the light and then probe the running light. If you do not get power then you probably have a break in the ground. You can run a ground wire from the tongue to each light and that should correct your problem. Or you van make a jumper between each bolted on part.
> 
> Hope this helps.



No it's a welded trailer. The tilt is the only major thing bolted. I'll test light it this evening.


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## SumDumGuy (Mar 21, 2014)

easiest thing to do would be to get a DMM and start measuring continuity and voltage.
I prefer Fluke, but you can get a perfectly functional meter at harbor freight for about 6 bucks.






On sale for $5.49 (don't forget the 25% off coupon and get it for less than a Lincoln).




https://www.harborfreight.com/7-function-multimeter-98025.html


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## JustJoe (Mar 22, 2014)

Thanks all. One side marker light needed to be grounded to the tongue. Everything works now


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## doc1976 (Mar 22, 2014)

It's almost always a ground problem


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## JustJoe (Mar 22, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=345905#p345905 said:


> doc1976 » 22 Mar 2014, 21:56[/url]"]It's almost always a ground problem



Figured it out using a set of jumper cables until the lights came on. One end to the light the other till the lights came on, :LOL2:


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