Trailer Brake Lights/Turn Signals Not Working when Connected to 2009 Suzuki Equator

Question:

I just bought the recommended wiring harness from etrailer for my pick up truck that included all the relays to match my pickup. I did the install and made sure everything snapped into place. When I hook up the trailer new trailer the running lights work but I dont get brake or turn signals. I took it to a local trailer company and they cant seem to figure it out. Any ideas why the brake and signal lights arent working? I checked all fuses too.

asked by: Keenan R

Expert Reply:

To determine if there is a problem on the harness or on the trailer here is what you will need to do. Disconnect the trailer from the truck. Then use a circuit tester, like # PTW2979 if needed, to test the pins on the 4-Way end of wiring harness # C56225. If the brake and turn signals are working at the 4-Way then you know the problem is on the trailer.

If they are not working on the 4-Way and you are certain that everything is installed correctly according to the instructions, linked for reference, then there is some kind of problem on the vehicle that will need to be looked at by Suzuki. Just to be sure, you can use the owners manual to find any fuse locations related to the tow package wiring and see first if there are any, and second if any are missing or blown. It sounds like you have already done this.

If everything on the truck works and the trailer is the culprit the most likely cause of this happening is a bad ground connection. You can double check the ground connection at the trailer connector and at each of the lights. They all need to be attached to clean, bare metal surfaces.

If you have a tilt trailer, folding tongue, and/or an aluminum frame, you will need to run jumper wires from the light grounds to the main trailer connector ground. If the lights draw more power than what the vehicle can handle that could be the problem but I suspect that it is most likely a bad ground if everything on the truck is working.

Make sure that the combined draw of the brake lights and running lights is not greater than the 7.5 amps this harness is rated for.

expert reply by: Michael H