Troubleshooting No Turn Signals of Curt Trailer Wiring on 2015 Mazda CX-5 With Headlights On

Updated 09/23/2019 | Published 09/21/2019

Question:

I installed a curt recommended harness package directional lights dont work when running lights are on

asked by: Roger W

Expert Reply:

The main problem you are having with the Curt harness # C56011 you have installed in your 2015 Mazda CX-5 is an insufficient ground for the trailer wiring. Try improving the connection of the main ground wire of the trailer wiring harness. Make sure it is attached to a clean metal surface. Or you can run all of the trailer wires back to the main ground. This is actually the ideal solution. But you can also check the current grounds for the lights to make sure they are making a solid connection to a clean metal surface.

What you described is the classic insufficient ground scenario so finding a way to improve the grounds will fix the problem. The issue is that when your headlights are on the maximum amount of amperage draw is put on the setup which if there's an insufficient ground this would be when this would show up.

expert reply by: Jameson C