Can Pulling Breakaway Pin Damage an Electric Brake Controller

Question:

The installation instructions caution that reversing the connection to a breakaway battery will destroy the control. The instructions also state to disconnect the trailer plug before testing a breakaway switch or you may destroy the control. Can you explain this? What happens if someone clumsy husband or something big black dog accidentally snags the breakaway cable, pulling the pin on the switch while the trailer is plugged in. Tekonsha Power Trac is the model of brake control.

asked by: Jim

Expert Reply:

The short answer, as I think you already suspect, is that if a clumsy husband or big black dog (or even a relatively crazy small dog like one of mine) pulls the breakaway cable with the trailer plugged into the vehicle it can ruin a break controller.

When the pin is pulled the circuit is completed sending power from the breakaway battery along the blue wire. The power goes to the brakes activating them however it can also (and often does) surge back up the blue wire to the brake controller since there's nothing stopping it.

Some brake controllers protect themselves from the surge; usually higher end controllers like the P3, # 90195, and P2, # 90885, for a couple examples. Your PowerTrac, # 39523, is not one that has this protection which is why the instructions have the warning.

expert reply by: Charles S