Troubleshooting Snowmobile Trailer Wiring And Lights That Stopped Working After Hitting Street Curb

Question:

I thought I had a bad ground and plug. Replaced the plug and tested the ground with jumper cables. All lights are still out. Tested the truck side-good. Next think I did was took the plug back apart and hooked up just the running light wires. The tester showed that I was getting power back through the rest of the trailer side wires but still no lights. So I guess I now have two problems.... Is it normal for power to feedback through the all other wires? Since the trailer appears to be getting power, why still no lights? This is a snowmobile clamshell style and the problem started when I hit the street gutter at the end of my driveway. Actually the lights flickered on occasion before going out all together. Any suggestions would be appreciated! Thanks

asked by: Nick

Expert Reply:

It sounds like you have physical damage somewhere in your system since you said this has happened since you hit the gutter in the street.

You said the truck has power at the connector so we can feel sure that the problem lies with the trailer.

You said you are getting power to the side wires on the trailer but you still have no lights. You will want to check the ground on each light to make sure they are attached securely to a clean bare metal surface. If you have a tilting trailer you may need to run a ground jumper to the trailer tongue. If you have an aluminum trailer, you can attach the ground wire to the axle.

You can enlist the help of someone who can work with you to test the lights on the trailer. While it is hooked to the truck they can move the wires to see if they can locate where a possible break in the wire exists. You can also remove the lens on the light and check each light when testing to be sure they are seated securely. If you test all of the wiring and lights and cannot locate the problem, you may want to run new trailer wiring.

If your trailer uses a 4-way connector, I recommend using a Wishbone Wiring Harness like part # A35W42B. The wire for the running lights is split into two wires, one for each side of the trailer. If you have side marker lights you can splice into each wire as it is run back to the tail lights.

I have attached links to a couple of helpful articles about trailer wiring you can check out.

expert reply by: Jeffrey L