Troubleshooting Trailer Brake Controller that Shows SH Code When Coupler Touches Hitch Ball

Question:

I installed the Tekonsha Primus IQ. I tested everything and it operates properly until I lower the trailer on the vehicle ball. As soon as it makes contact I get an SH error. Its a brand new trailer and i dont see any Shorted wires. Tow vehicle is a 2015 Mercedes Benz GLK 350

asked by: Jamie M

Expert Reply:

You most likely have a short on your trailer wiring from the 12 volt power circuit to the frame of the trailer which is basically causing the frame to carry voltage. So when the coupler touches the hitch ball that voltage shorts to the truck's frame as the truck frame is grounded. Go over the wiring of your trailer from the connectors back to where the wiring terminates and you should find exposed wire touching the frame somewhere. You'll want to use electric tape to seal this up.

expert reply by: Jameson C