2012 RAM 12V and BK Don't Illuminate LED on 7-Way Trailer Connector/Tester

Question:

Hi, My 2012 RAM 1500 bought used has built-in 4 and 7 pin trailer plugs. I bought a CURT 7 pin plug tester. Everything is great, except there is no light for the 12V line and no light for the BRAKE. I thought it might be a fuse but can not locate on any of the diagrams from internet which fuse. I am assuming it was properly wired. Is that a wrong assumption? Any ideas would be helpful. Thanks Darren major

asked by: Darren M

Expert Reply:

You won't get any reading on the BK lamp unless there's a brake controller installed. If one is installed, you might only pick up a flicker as the brake controller sends a very small amount of voltage through to check if a trailer is connected. If you have a proportional controller, the BK lamp will NOT light up with the brake pedal, only with the manual brake switch on the controller.

The 12-v feed to the trailer connector is protected by a 40A fuse located in the fuse box in the engine compartment near the battery. The fuse is located in the J01 cavity. Make sure the fuse is in place and not blown.

expert reply by: Mike L