Troubleshooting Tekonsha Primus IQ Brake Controller Installation in 2017 Jeep Cherokee Trailhawk

Question:

I had a RV Dealer hookup a Primus brake controller on my 2017 prewired Cherokee Trailhawk but it keeps applying the trailer brakes at all times. My local Jeep dealer says its because of the LED tail Do you have any ideas?

asked by: Stan D

Expert Reply:

The installation of the Tekonsha Primus IQ Trailer Brake Controller # TK90160 in your 2017 Jeep Cherokee Trailhawk with pre-wired factory tow package will use the Tekonsha quick-connect wiring adapter # 3014-P to connect it to the port under the dashboard.

If the vehicle does not have this factory feature and the RV dealer had to install the controller via hardwiring it then it is possible the wrong circuit was connected to the controller's red wire. The red wire takes in the vehicle's brake light signal, from the cold side of the switch at the brake pedal, and this signal tells the controller to generate braking power for the trailer. The COLD side of the brake light switch is the one that carries voltage ONLY when the brake pedal is pressed and at no other time. If the wrong wire was used the controller could see an always-on brake signal which would cause it to apply the brakes continuously.

The other possibility is that the incorrect harness was used to plug the controller in. The correct art is # 3014-P. There are other similar-looking harnesses but unless this specific one is used the controller will malfunction. If there is no display on the controller but the brakes are still applying then the problem is the wrong harness. The correct one is shown in the linked video.

My contact at Tekonsha advised that the LED lighting on the vehicle has no bearing on this issue.

expert reply by: Adam R