Troubleshooting Trailer Breakaway System Installation That Interferes with Brake Controller

Question:

Hello, I have this controller installed on my 2007 Avalanche, and am having a problem with the how it is interacting with a Hopkins Engager break away system. When I plug the trailer to the truck, it is like the brake controller is not registering that the trailer is connected. If I disconnect the blue brake wire from the Hopkins Engager, my trailer brake controller works perfectly. Once that blue wire is reconnected, it is like it overrides the connection between the truck and the trailer. At this point, I am just trying to understand if it is a brake controller issue, the Hopkins Engager, or something in the Avalanche? The truck had the factory installed 7 pin connector, so the brake controller was installed per an instructional video I watched on the etrailer web site. Any ideas for trouble shooting would be GREATLY appreciated!

asked by: Bruce S

Expert Reply:

Trailer brake controllers and trailer emergency breakaway systems like the Hopkins Engager # 20099 do wire together. You can refer to the two linked articles on installing and testing breakaway systems for help confirming your installation is correct and that the system is operating correctly.

What can happen is that corrosion can develop inside the trailer's plug or vehicle's socket and this corrosion can cause shorts and other issues that can easily interfere with normal brake controller operation. This could also cause apparent problems in the breakaway system since they are wired together.

Since you have a factory 7-way and since the vehicle is now 11 years old I suggest first troubleshooting the 7-way socket on the Avalanche. You can visually inspect the socket on both the exterior and on the back side where it connects to the vehicle wiring, looking for any signs of discoloration or corrosive build-up. A spray-on electrical contact cleaner like Caig De-Oxit or a similar product made for cleaning up wiring connections may dissolve any corrosion that could be the course of the problem. If you suspect a bad 7-way socket you can replace it with # HM40975 or # A10-7072VP.

If you find you need a new 7-way trailer plug you can most easily install one using junction box kit # HS381-9000.

You'll also want to inspect all wiring for the breakaway, looking for cracked or worn insulation that could be causing a short.