Troubleshooting Trailer Brake Controller Not Showing Trailer Connection

Question:

I just attempted to tow my travel trailer with my new 2018 3500. Prior to starting out I checked all lightening includin brake lights and everything was in working order. During drive to my rv dealer I noticed that brake gain display was not moving and it appeared trailer brakes were not operating. No error messages appeared on the DIC. Brakes were checked at rv dealer and they appear to be fine. Is this likely a controller, wiring or 7 way receptacle issue? Thanks. Really enjoy your videos.

asked by: Sam M

Expert Reply:

First place to check is the trailer wiring connector. Normally it's corrosion or a bend pin in the 7-way that causes this. Since the truck is brand new it's most likely on the trailer side.

Does the trailer happen to have electric over hydraulic brakes? They are notoriously finicky with integrated brake controllers so that would be the next thing to check. Best solution then is to go with a controller designed for EOH brakes like the P3 part # 90195.

Can you verify that the brake output pin of the 7-way has voltage when the brakes are applied like with a circuit tester # PTW2993?

expert reply by: Jameson C