Trailer Right Brake Light

[RBerg]

I have a 2003 2500HD. On my 7 way trailer connector, I have no signal for the right brake light. Left brake light works fine and both left and right turn signals work fine. Just right brake signal not present on the connector. Brake lights on the truck work. The right turn and right brake use the same wire on the connector so I'm thinking it's not a wiring problem. All fuses check out ok.

Is there a converter box somewhere which combines the turn signals and brake lights together for the trailer? If so where is this located?

If anybody has any ideas on this I would appreciate any help.

[Shaners]

Are you checking the pin with a test light or just going by the fact that the trailer light isn't working? If it is just the trailer light you're going by then it is a bad socket or ground for that light.

[RBerg]

Are you checking the pin with a test light or just going by the fact that the trailer light isn't working? If it is just the trailer light you're going by then it is a bad socket or ground for that light.

 

 

I'm checking with a test light off the connector. I have 2 connectors, one for the 5th wheel in the box and one under the bumper that I use for an equipment trailer. I have the same problem on both trailers which is why I tested the sockets on the truck.

[Shaners]

First place I would check then is the splice where the 5th wheel wires tap into the harness going back to the bumper. That should be along the frame between the bed and the cab I would think (I never really looked at mine but I know my 5-er harness is still attached to the back of the cab).

[Kodiak450]

Crawl under the rear of the truck where the connector is. I think there is a flat connector that might plug into the round connector. Do you ever apply dielectric grease to the connector annually? If not you should, so all the pins stay coorosion free. Other thought, you might have a bulb out or a bad wire somewhere. Or maybe connector needs to be replaced, they aren't expensive to replace.

 

The 5th wheel wiring is located between the bed and cab, resting on top of the frame. It's usually taped up with black tape and bunched up.

[Bluedog]

Hate to ask, but you did check the fuses behind the door at the left end of the IP correct? There is a set in there too for each of the trailer lights.

 

This had me stumped for quite a while one day trying to get my left turn signal to work.

[RBerg]

Yes, I did check those fuses by the IP but they were ok.

 

Couple years ago I had pulled back the 5W connector and remounted i the sidewall of the truck box. Guess I'll start ripping connectors apart to see what I can find.

 

Just thought since I have separate amber signal lights on the truck there might be some kind of converter that brings the brake and signal light together on one pin for the trailer. Maybe that's done it the BCM.

 

Thanks for your responses.