I tried NTB, Firestone, express tire and oil, and several others in North Alabama. None of them could do it. Had to take it to Ford dealership. They did it in less than an hour.
For me it was much easier to find the Gray and Violet wire by unplugging the top most harness above the J3 harness (not the black one directly above J3) and the 2 harnesses below J3. With those removed as well as the J3 connector. I was able to reach in and find where the harness wires for J3...