Troubleshooting Trailer Wiring Harness that Stopped Working When Headlights are On

Question:

Hello, I bought a curt trailer harness from Rock Auto part #56225 and as it said was fairly easy to install on my 2014 Nissan frontier. But after making all the correct connections everything seemed to work properly until I turned on my headlights. Then everything didnt work as it should. one side would work the other very dim etc. Can you help me figure this situation out? Thank you

asked by: Gary M

Expert Reply:

What you described is a classic insufficient ground scenario. If you improve the grounds of the trailer taillight assemblies as well as the main ground circuit that runs to the trailer frame your problem will go away. The issue is that when the headlights are on there is more of an amperage draw. This is what is causing your ground issue to come up.

expert reply by: Jameson C