I have been chasing this issue since the beginning of June. 2015 fusion. It started with a heavy grind, and I have found a few issues with calipers on the front and the rear. After new rotors and pads all the way around and 3 our of 4 calipers have been replaced, it is still dragging in the back. My assumption is the parking brake, but I have read many posts of people who have replaced them, and no fix. The only two posts i have found to repair this is replacing the wiring harness. You have done both with no luck. Did you do both wheels? I had one tire in back drag; I could barely turn it and other was fine. I replaced the caliper and both drag now...the car throws codes for the speed sensors being off (abs, traction, and hill assist) of one another. I plan to replace my harnesses and try it before doing the entire actuator. Good luck if you havent already fixed this.
