I am answering this only for future searches.
Yes, indeed that recline motor is buried up inside the headrest.
I had to skin the seat back, and the motor is up in the area of grey material.
Once the seat has no covering it is possible to pull back the material of the headrest and you can see the motor. You can see the two connectors where the wires attach. The two wires are run inside of a plastic conduit along the side of the seat.
After going through all the effort of skinning the seat I discovered to was indeed my black wire that had a short.
It was about there at the bend in the conduit where the arrow points. In the end, I did not have to take the seat skin off, as the short was accessible. The conduit had no damage and looked fine. I started cutting it off and found this.
So I suggest you carefully remove the plastic sheath or conduit and look for a break in either wire. If no break is found, you will need to remove the leather or whatever covering is on your seat.