I am trying to install a power seat track in to my 1992 5.0. The original one worked but the mounts broke where it bolted in to the car. When I installed the first new seat track only the right side of the seat track would move when I hooked it up. I returned it to LRS and they sent me a new one. I installed the new one and have the same trouble. When I plug the old seat track in both sides move back and forth with no problem. I find it hard to believe that I have gotten two $450 defective parts. Is there something that I am doing wrong with this installation