I am sure your mechanic has checked this, but I lost power to my drivers seat and discovered it had disconnected under the seat from turning the seat when parked to face the rear of the coach and twisting the power cord around the base, and not turning the seat the opposite direction for driving. My seat heat also quit working and I found that twisting the power cord caused one of the wires in the plug pulled out just enought to cause it not to make contact.