Troubleshooting Trailer Lighting Circuit Blowing Fuse Even When Trailer Is Disconnected

Question:

The fuse for the lights on my marine trailer keep blowing even when the trailer is not attached. The connection to the fuse box looks ok, the ground and wiring to the harness look ok too. Not sure what to do. If the connections are corroded but not touching anything, can it still cause a short?

asked by: Duncan R

Expert Reply:

If the connector has 12v power it is possible that corrosion can cause the power to jump circuits and blow a fuse, though that is not usually the cause. If you do find corrosion in the connectors it is likely that there is also corrosion inside causing issues and the connector should be replaced. If you can tell me which connector your trailer uses I would be happy to recommend a replacement.

What I would do first is check all of the wires that are powered by that specific fuse that is blowing, and look for any damage or areas where it could be grounding out as more than likely there is an exposed section of the wire somewhere that is causing the circuit to pop.

If it is just a lighting circuit you can replace any damaged sections with # 16-1-1 and heat shrink butt connectors # DW05744-5.

I included a link to a helpful article on wiring for you to take a look at.

expert reply by: Samuel C