Troubleshooting Trailer Lights That Only Work When Standing On Trailer Hitch  

Question:

Helpful Expert Reply:

It sounds like you have a classic ground issue somewhere on your trailer wiring. Since there is a weak ground on the trailer the ground is being completed by the hitch ball/coupler connection, and the additional tongue weight you create when standing on the hitch is essentially improving this connection.

Check to make sure the main connector ground wire on the trailer is secured to a clean, bare metal surface. It might be worth it to remove the wire and sand down where you have it attached before attaching it again to ensure it is clear of any paint, corrosion, or debris that might be interrupting the ground. You will want to do the same thing with the light assemblies themselves, whether they ground through their mounting hardware or use a dedicated ground wire.

If this does not resolve the problem please let me know and we can continue to troubleshoot.

expert reply by: Chris R

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