I have a 2008 3500 with an odd problem.
Most times when the truck hits a dip in the road (not potholes or bumps) and a vertical oscillation is created, the trailer brake system creates a fault and disables the trailer brakes, whether I have a trailer attached or not. It is a factory installed brake controller. I'm the only owner and no one has messed with the electrical connections.
I have come about an odd way of resetting the system while driving (can't do it while the vehicle is not moving) and it's most definitely unsafe and doesn't prevent future occurrences.
I'm guessing something, somewhere grounds out, but I could be wrong. Can anyone point me in a direction to start my troubleshooting without having to rip out the entire trailer wiring?
Thanks.

 

Have you tried cleaning the socket(s)? They do fill up with dirt and grime.

Just an idea,

Allan

 

Do you feel this oscillation through the steering wheel?