Troubleshooting Trailer Battery Draining with Brake Controller and Electric Trailer Jack Installed

Question:

I have a 7 way cable and wiring junction box on my trailer. I have a brake controller wired in and is working correctly and has an option to connect a charger. All of it works perfectly. I added an electric trailer jack. I wired it up and connected the power to the 12v (blk wire) aux charge line. Hoping to charge battery while truck is running and be able to connect the charger when needed. The Battery keeps going dead I think I am constantly charging the battery on the brake controller. Any thoughts?

asked by: Tr H

Expert Reply:

Thank you for reaching out!

I'm not 100% certain what you have installed on your trailer but it sounds like you may have some things wired incorrectly on your trailer. Your brake controller should be going directly to your trailer brakes and the only other thing connected to that line would be one of the wires for the breakaway switch, like what comes with the Hopkins # 20400 (see first photo). Aside from that the 12V power wire is where you want to connect a battery for charging as well as the line you want to connect your electric trailer jack to.

If you have your wiring configured differently then that might be why your batteries are draining.

I've attached a second photo showing how a trailer wiring should normally be ran. If you have something different or you aren't sure what else might be needed just let me know what brake controller you have and how you have everything connected and I can further assist you!

expert reply by: Jon G