Breakaway System Has Power with Pin in Switch but No Power when Pin is Pulled

Question:

Breakaway switchHow can I show voltage it with the pin in my breakaway switch but when you pull the pin there’s no power

asked by: Lee

Expert Reply:

Where are you seeing the voltage at? A breakaway system battery would be connected to the switch on the trailer side and the brake output circuit from the brake controller would be on the vehicle side. It could be seeing voltage from the breakaway battery or from the brake controller or even a charge if equipped. It depends on how everything is wired up.

When the pin is pulled out it will complete the circuit and allow power to go from the breakaway battery to the trailer brakes. If you are not getting any power to the brakes with the pin pulled then it sounds like there is a short in the wiring or possibly some corrosion inside the switch itself causing the problem.

I would inspect all the wiring and fix any broken or pinched wires. Test the breakaway battery as well to make sure it is holding a charge. An auto parts store should be able to do that. If all of that checks out then the likely culprit is the switch. Most breakaway systems have switches that are interchangeable so you could replace your switch with # HM20010.

expert reply by: Michael H