Troubleshooting Constant Power on Right Brake Light Vehicle Side

Updated 09/15/2020 | Published 09/11/2020

Question:

Hi I recently installed the Hopkins 4 flat wiring and when testing with my trailer the right rear brake light comes on as soon as the trailer was plugged into the car. After investigating for a good ground and pinched wires. I found that there is 10v indicated on the green wire pin on the car side constantly. Do I need a new controller? Or is there another issue? Best,

asked by: Nathan

Expert Reply:

If the green output wire of the wiring harness # HM11143764 is having constant power, that is an issue. I recommend checking the green input wire prior to the module because the green wire should only have power when the brakes are applied or when the right turn signal is on. If there is constant power before the module, then I recommend checking the connection for bent pins or corrosion. If the input wire is working correctly and the output wire is not, then you know the module is bad and needs replaced.

expert reply by: Jason S