Problem with trailer lights

[Workdawg]

I just put new lights and wiring on my trailer and everything works fine until I start the truck. Everything works ok then except the brake lights.They will not come on. They work if the truck is not running but will not if it is running. Anyone have an idea as to what to do to correct this. Thanks....Wayne :?:

 

[perchin]

I'd make sure your ground is good. 99% of lighting problems are grounding issues. If it is a tilt trailer put a ground up front and run a jumper from the front ground to each light also.

 

[Workdawg]

Thanks Perchin...I'll give that a try..I thought it was grounded ok, but I will check it tomarrow.

 

[Pruitt1222]

What kind of truck are you towing with? Sounds to me like it has nothing to do with your wiring job and more with the tow rig. Does it have a factory tow wiring harness, plug and play, or hard wired?

 

[perchin]

Hmmmmm...... I guess time will tell. Is it a tilt trailer?, my last tilt trailer had the 100% same issue to a tee......... It was the grounding NOT the rig. Example::: Have you ever hooked up to a camper that has not been pulled in a while? Well they are usually grounded through the ball coupler, resulting in poor and weak lights for about the first couple of miles untill the rust is gone on the inside of the coupler and off of the ball.

 

[Truckmechanic]

What kind of truck are you towing with? Sounds to me like it has nothing to do with your wiring job and more with the tow rig. Does it have a factory tow wiring harness, plug and play, or hard wired?

I was thinking maybe the truck as wel with them working with ignition off. What type of plug, 4 pin or 7 ?

 

[Workdawg]

1. Truck is a 2000 Chevy S-10
2. Trailer is a tilt trailer.
3. Plug is a 4 pin. not factory installed.

 

[Pruitt1222]

It could be a poor ground, Do you know if your brake and turn signals use the same bulb?

 

[perchin]

I guess if it were me I wouldn't want to be tearing apart a bunch of crap to only find out it was a grounding issue. I would simply run a temperary jumper from the existing ground up front to the tail-lights first to see what then happens. If that was not the issue, well then I would go tearing into the trucks wiring.

 

[Workdawg]

Thanks for all the help guys.. The problem was the ground on the truck...got that fixed and everything works fine..

 

[Pruitt1222]

Glad you got it taken care of, I thought it may have been a ground issue but would have never placed my chips on it. I had the same problem outof my wifes truck and it was wired wrong, it needed a 5wire to 4 wire converter on it and it did the exact same thing. Glad it was a easy fix and glad I aint a betting man.

 

[perchin]

Thanks for all the help guys.. The problem was the ground on the truck...got that fixed and everything works fine..

Tis' almost always a ground issue. Glad you got er up and going, now get out there are reel in the big ones. 8)