Boat trailer running lights not working?

Question

I have an issue with my boat trailer lights. The brake lights and turn signal lights work but none of the running lights. The bulbs appear to be good so I don't think that's the issue. I did find one white wire that isn't connected to anything on the back of one of the rear lights but can't figure out where it may go. Also, when I took the lense off of the light where the loose white wire is, water poured out.... Any suggestions?

Answer 1

White must be the ground. water will short anything out to ground.

Brown is tail , yellow is left, and green is right. and white or black is ground. Are you getting power to the running lights to the connector? Past the connector? Do you have a Good ground?

Your going to have to trace it back with a test light or probe.

Answer 2

Corrosion and grounding are the two biggest problem with trailer lights. Chances are the running lights have a buildup of corrosion where they bolt on and are no longer grounded.

Answer 3

If everything works but running lights I'd start looking at the connection between the trailer and vehicle towing.

Answer 4

If you think you have the wires figured out but the light still wont light.  Try sanding or scraping the points of contact between the bulb and socket.  Rust or corrosion wont make a connection.