Trailer Light Problem

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New member
Jul 19, 2018
I have an issue may y?all can help. I bought a vintage trailer and changing the the plug from a 4 flat to the original 7 way plug. Tail lights work previously. I reran wires to new plug and only my right turn and right tail lights work. Both sides work if I put on my 4 way flashers. I thought maybe bulbs so I got wired and straight connection from my tail lights to my battery on my camper. They both worked. Does anyone know what would be causing this issue? I hope I explained it clearly.

Kevin Means

Site Team
Aug 3, 2010
Lakeside, California
Hi Fhunt. Welcome to the RVForum. It's impossible to say from afar, since we can't see it, but since the lights were working before, the new wiring must have been wired incorrectly, or there's a bad connection - somewhere. I think I'd start troubleshooting by ensuring that the new 7 pin connector was wired properly, then if so, I'd use a VOM to ensure that all the connections were good.



Well-known member
Nov 15, 2014
A wise man once told me that when lights start to act weird the problem is usually a bad ground.
Make sure you are wired correctly and then make sure your grounds are solid.
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