Troubleshooting Trailer Brake Controller Showing Trailer Disconnected On Bumpy Down Hill Road

Question:

I have an interesting trailer brake issue. The brakes came with my then new 2019 Kodiak Cub. When I am on a bumpy road, and braking often, IE going downhill, and going slow, my 2020 truck will state that the brakes have disconnected. In most cases I just need to stop, put it in park and they reconnect. This never happens unless I am pressing the brakes, so if I am going slow uphill on a bumpy road, same speed as if going downhill, it does not occur. And it has never occurred on paved or graded dirt roads at normal speeds. Thanks for any thoughts you may have on this!

asked by: Jim R

Expert Reply:

This is definitely a peculiar issue and as it is an intermittent issue makes it very difficult to test the issue. I would start by bench testing the controller. You will need a 12 volt battery and bulb to act as a load. The load required can change from controller to controller so you may need to contact the controller manufacturer as well to determine exactly what is needed. You will likely want to have a second set of hands to recreate some of the vibrations on the tester you are experiencing.

Next I recommend checking the terminals inside the 7-way connector. These can often show build up of corrosion/oxidation which degrades the continuity and cause intermittent issues. You also want to check for any signs or damaged or loose connections on the individual connectors. Some Dielectric Grease # 11755 can also help to reduce the chances of a wiring short giving the controller incorrect information and causing it to believe the trailer is no longer connected.

If you still have issues after checking these things I recommend visiting a local trailer service center to further diagnose the issue.

expert reply by: Bud M