Troubleshooting Trailer Brakes Randomly Applying

Updated 10/31/2024 | Published 10/21/2024

Question:

Hello, everyone. I’m working on fixing my trailer to save some money and learn about it in case I encounter any issues in the future, so I can jump in and handle them right away. I bought my trailer brand new three years ago, and everything worked perfectly fine. However, this year I started having issues with the electrical connection because I forgot to plug it in once, which led me to install a new plug or connector to keep the trailer lights working at least. After connecting all the wires properly, I noticed the brake wiring wasn’t working correctly. The brake controller sometimes senses the right pressure, but other times it activates without pressing the brake, or it makes the trailer brake very roughly. Because of this, I disconnected the blue wire. Upon inspecting everything, I saw that the battery storage case was flooded, and I thought that might be causing the issue. So, I bought a new wiring box for the connection and a brand-new breakaway system. Unfortunately, the results are the same—I still can’t control my trailer brakes properly. The brake controller does everything except what it’s supposed to do. I need help, experts! Thanks.

asked by: Daniel G

Expert Reply:

Hey Daniel, I would be willing to bet that your issue is a short between the 12 volt accessory circuit wire that runs to your trailer battery and the brake output circuit which carries the voltage to the assemblies. What is most likely happening is there is some exposed wire between the two circuits intermittently making a connection. This is most likely at the back of the new trailer wiring connector you installed so that would be what I would check.

expert reply by: Jameson C