The back lifter on my 07 Chevy Tahoe seems to be stuck or just not working. I can hear it click when I press the switch up and down, but it will not move. It would not be so bad if the seat was in a position that was tolerable, but it is cranked all the way in the up position and my head is almost touching the ceiling of the vehicle. I have also noticed that it seems to no slide back as far as I would think it should. All of the other functions work, the front of the seat lifts up and down fine. Thanks for any help in advance!