Troubleshooting Brake Lights that are Staying On

Question:

just installed HM11140395 all connections good ...but as soon as you turn on lights the brake lights come on and only go off when headlights are turned off any hints...unplug trailer conn. wiring everything works fine.....

asked by: Kerry D

Expert Reply:

I can help you troubleshoot this wiring connection issue.

First thing I would do would be to use a circuit tester like # PTW2993 and test the 4-pole at the end of the vehicle to make sure all the functions are properly working. If they aren't, then I would move on to the wiring before the converter box. If this wiring is all running correctly, you may have a bad converter box on your harness.

If all the poles are functioning normal, then you may consider checking the wiring on your trailer to be sure it is wired properly. Here are some typical color codes.
White: Ground
Yellow: Left turn
Green: Right turn
Brown: Tail/Marker

I have attached a Help Article on wiring for your convenience. Within the Help Article you will find a wiring diagram; this will help you be sure there are no problems with your wiring connections.

One more thing to check out would be the grounds on your trailer. Be sure they are all mounted on a good clean metal surface, any loose or broken connection will cause issues.