Trailer wiring driving me nuts!

Really difficult to diagnose an electrical issue over the net. If it was me, I would start at the tow vehicle plug with a multimeter and make sure I had 12 volts on my right turn pin then start tracing it back to the light. I also had an issue or two on my first BassCat trailer. What has the issue been with the connections coming loose? Overcrimped, undercrimp, inferior butt connectors? Any ideas?

Thats what I found on a 2009 model. Overcrimped and many strands of copper broken eventually leading to failure of butt connection. Have had no issues on a 2013.

I was having very similar issues with my 08. Every other month, there were broken connections, loose wires, and lights not working. A couple of years ago, I purchased all LED clearance lamps & tail lights and went to work. First thing was to get rid of all crimp connectors. All connections are now soldered with glue lined heat shrink for waterproof connections. The marine heat shrink is available at Harbor Freight in a large assortment for about $6. In an evening – I replaced every crimp and had a waterproof solid wiring system. Ive not had my first issue with it since. The key issue is to leave the wiring with a little “room” so as not to stress the connections.

First check and make sure you dont have a burnt fuse. I had a Ford truck that had fuses for the trailer connector and it was separated for turn signals. So check at your trailer plug whether your getting power, than move further back. Once you find the problem, fix it, but better than it was. Always twist your wire tight before crimping. There also connectors that are available that after crimping, you heat it. It shrinks and releases a sealing compound, sealing the wires from moisture. I use those.

I know many people think a soldered connection is more permanent than a butt splice, but many years ago when I was in the service doing electrical work, it was considered a temporary fix. Consider this. A soldered joint adds a stiff part to your multi-strand wire. Add vibration, as in a boat trailer on our best back country roads, and its a fail point where the solder meets the copper. Fatigue, over time will break it. Not something I made up.