Troubleshooting Trailer Light Function With 2003 Chevy 3500 Flat Bed

Question:

On my 2003 chevy flat bed pickup 3500, I pull a few different trailers and I have the same problem with them all so I think my problem is with the truck. When I put on my left turn signal, the trailer lights will flash on the right, but only for a few seconds before going to the correct side. This happens on both directional signals. Also brake lights are intermittent when I brake. I took a tester with a light bulb in it and it works just fine. The connectors on the truck where the pigtail goes all look good. The signals on the truck its self all work fine. Several different types of trailers and 2 trailers are brand new. Any info you can give on where to start would be great. Im lost. Thanks

asked by: Austin K

Expert Reply:

Since your incandescent tester seems to work just fine, it appears that individual function at your trailer connector works fine. There could be a short in the connector that is only when there are multiple pins connected. Since this is the case with multiple trailers, I would make sure your connections are cleaned up really nice and then if you still have an issue I recommend swapping your connector for a new one like the Replacement Multi-Tow 7-Way & 4 Pole Trailer Connector # 74682 or the 6 way # 40965.

expert reply by: Jason S