Brake Controller Goes from Zero to 14 Too Easily on a 2017 Honda Pilot

Question:

I installed a 7 way harness and teknosha primus IQ in a Honda pilot using pre terminated harnesses 3070-P for the brake controller and the t-one vehicle harness. with the seven way hooked to my trailer not hitched up because I dont have the receiver installed yet all of the lights and trailer power work correctly. When I tried to adjust the brake control output on the IQ IAW the instructions the power output goes from zero all the way to 14 by just moving the thumbwheel a tiny bit. Im not sure if this is due to the trailer not being physically connected or an issue with the controller or wiring. the boost button will change boost levels fine, the controller shows .c. I wonder if the ground for the brakes goes through the ball and hitch and not the dedicated ground in the 7 way. any help would be appreciated.

asked by: Andrew C

Expert Reply:

I can help you troubleshoot to determine where the problem is. Since your brake controller jumps up to power level 14 so easily there are a couple of things you can check on the brake controller itself.

First, make sure the brake controller is mounted within the range specified in the instructions. I have also included a picture showing this. Note that the controller cannot be tilted to one side either. When controllers are outside of their mounting range all sorts of weird things can happen.

If that doesn't solve the issue then it could be a short in the newly added trailer connector making the controller think power is being drawn. You can use a meter such as # PT89ZR to see how much power there is on the pin in the 5 o'clock position on the 7-Way. There should only be power going back when the manual override on the controller is operated. If there is power when there should not be then disconnect the controller and test again. If there is still power then the issue is not the brake controller but somewhere in the trailer wiring harness.

In addition to the information above I have included some links on testing and troubleshooting brake controllers for you.

expert reply by: Michael H