Troubleshooting 2018 Nissan Frontier SV with Brakes that Lock Up when Key is Turned On

Question:

I installed the Kurt tryflex brake control 51140 on my 2018 Nissan Frontier SV with the C51382 wiring harness. I am not getting any voltage on the 12 V connecter in the back to charge the battery on the camper. As soon as I turn on the ignition it applies voltage to the brakes on the trailer. Is it possible that the harness is not configured correctly? The kit also came with the three relays which I also installed on the passenger side.

asked by: Henri C

Expert Reply:

The brake controller and the brake controller wiring you mentioned does not affect the 12 volt accessory circuit of the 7-way that you are wanting to use to charge your trailer battery. Now with that said if your trailer brakes are locking up as soon as the ignition comes on that to me indicates that you have the brake output and the 12 volt accessory circuits either wired backwards (most likely) or there's a short between the two circuits.

The 12 volt accessory circuit should be in the 1:00 position on the 7-way and the brake output would be in the 5:00 position. You should check to see if maybe the trailer or the vehicle 7-way happen to be wired backwards.

The Curt Triflex is notoriously a problematic brake controller so the brakes locking up could be it having an internal error. So what you can do is unplug the controller and see if the brakes are still locking up. If not, then the issue is the controller and a new one like the # TK63VR would be your best choice. Otherwise it's wiring. The # TK63VR is very reliable and also great performing which is why we recommend it so highly.

expert reply by: Jameson C