2017 Thor Aria 3901 Brake Controller Harness Finally Located
After several hours of searching the dash from below (even used a camera scope), I finally found the brake controller harness on my 2017 Thor Aria 3901 after removing the actual instrument cluster. I was apprehensive about removing the cluster at first, but it was easy to do just by removing the handful of screws located around the bezel of the cluster. The cluster comes out as one piece and I just 'tilted' it forward and found the brake controller harness lodged up behind it (see attached image). Good luck and I hope you find it!