On a trip last week the seat back quit working on one side. So I clipped the hog rings at the bottom of the seat and pulled the upholstry up like pulling off a sweater until I could get to the flexible cables. After quite a bit of investigating I figured that the motor and gear boxes were OK. I finally decided that the flexible shaft inside the housing to the inner gear box was too short and had slipped out of the gear box toward the motor end. Since I could not stretch the cable I shortend the housing about 3/8 inch and reassembled it and it works fine.

To synchronize both gear boxes leave one unconnected and move the other side back and forth until it is about in the middle of the travel with the other side not moving, then reconnect the loose side.

Don