Just recently my trailer running lights have stopped working. My brake lights and turn signals work fine, but I can not figure out what is wrong with those running lights. I bought a new adapter for the truck and put a new plug on the trailer, still now running lights. Any suggestions?
Trailer light issue
On most trailers the brown wire is your running lights so follow that.
Check the grounds, but you can also try some electrical parts cleaner on the plugs. That solved part of my issues earlier this year.
Check the grounds. Seems to be the problem for most trailer light problems.
I had the same issue. Fuse on my truck blew several times. I had a short in the taillight wire inside the trailer tube. Needed to rewire the trailer. Issue solved. Turned out to be mice chewing on wires.