Troubleshooting Trailer Brakes that Lock Up When Plugged Into Tow Vehicle

Question:

Trailer breaks lockup when plugged in I replaced the breakaway switch. I cut the wires going to the switch and I also cut the wires coming out of the box. Still locks up. Help!

asked by: Tony

Expert Reply:

It sounds like the issue you are having with the trailer brakes locking up is unrelated to the breakaway switch on the trailer.

If the brakes are locking up as soon as you connect to the tow vehicle, I first recommend testing the 7-Way connector on the tow vehicle with a circuit tester like # PTW2993. Make sure you are only getting power at the brake output pin (5 o'clock) when applying the manual override on the brake controller. If you are getting constant power there then there is likely a short somewhere in the vehicle wiring. Check both the vehicle side and trailer side connector for any debris or corrosion built-up inside the pins that might also be causing a short.

If this doesn't resolve the issue please let me know and we can continue to troubleshoot.

expert reply by: Chris R