Trailer Running Light Issue
I have a 5th wheel horse trailer with some kind of light/wiring issue and I'm hoping someone can help me debug this. On an earlier trip, we didn't have the rear running lights showing on the back o...
Forum Discussion
You can basically ignore all lights except the two taillights that aren't working. They all run on separate wires and therefore do not affect one another. The exception is the ground and the running lights.
The above colors really don't matter as they can change colors as they go around the trailer. But what I tried to did above is illustrate how each light is controlled by a different wire; Which is why some lights work and others don't.
You should definitely check the grounding because it's the easiest thing to check. Pull a light off the back of the coach and find the ground. If there are three wires the ground should be labeled on the housing. If there are only two wires then the ground is through one of the mounting screws and you will see bare metal for the screw to touch.
But you're dealing with LED's and I don't think you have a grounding issue because if you did the brake lights would also not work. The running lights are usually wired with one wire that goes down the trailer and around the back. Each running light is T'd off that one wire. Somewhere in the back of the trailer the T-connection for the taillights is loose or disconnected.
Hopefully you can see the back of the taillights without removing them, But if not I would remove each taillight carefully being sure not to pull too hard on any of the wires. You need to be careful because if there is a loose connection you don't want to have the connection pull apart and drop the wire back into the trailer where you can't get to it.
With the running lights on, wiggle and pull the connections, squeeze them with a pliers. If the light suddenly comes on you found your bad connection. Unplug the trailer, cut out and redo the bad connection. If all the connections are good then you are going to have to find the other end of the T-connection. I would start up at the running lights across the top rear of the trailer. Pull each one carefully and check the connections. Sooner or later you will find the bad connection and repair it.
way0utwest1 wrote:
- brake lights work (Combination of Green and Yellow wires)
- both turn signals work (Green and Yellow wires)
- reverse lights work (Could be any color wire)
- running lights on side (top and bottom) of trailer work (Brown wire)
- trailer brakes work (Blue wire)
- rear running lights do not work. (This is what we all call your taillights and are powered by the Brown wire) Yet it appears the entire LED panel lights up for the brake lights. (Combination of Green and Yellow wires)
The above colors really don't matter as they can change colors as they go around the trailer. But what I tried to did above is illustrate how each light is controlled by a different wire; Which is why some lights work and others don't.
You should definitely check the grounding because it's the easiest thing to check. Pull a light off the back of the coach and find the ground. If there are three wires the ground should be labeled on the housing. If there are only two wires then the ground is through one of the mounting screws and you will see bare metal for the screw to touch.
But you're dealing with LED's and I don't think you have a grounding issue because if you did the brake lights would also not work. The running lights are usually wired with one wire that goes down the trailer and around the back. Each running light is T'd off that one wire. Somewhere in the back of the trailer the T-connection for the taillights is loose or disconnected.
Hopefully you can see the back of the taillights without removing them, But if not I would remove each taillight carefully being sure not to pull too hard on any of the wires. You need to be careful because if there is a loose connection you don't want to have the connection pull apart and drop the wire back into the trailer where you can't get to it.
With the running lights on, wiggle and pull the connections, squeeze them with a pliers. If the light suddenly comes on you found your bad connection. Unplug the trailer, cut out and redo the bad connection. If all the connections are good then you are going to have to find the other end of the T-connection. I would start up at the running lights across the top rear of the trailer. Pull each one carefully and check the connections. Sooner or later you will find the bad connection and repair it.
