The ram drives the drawer past its neutral position so that it bottoms out on the bottom of the cabinet. There is a limit switch which senses this "bottoming out" and reverses the direction of the motor. If the unit is an "undercounter", you can slide it out and see the switch. It may be out of adjustment. It works, however, in conjunction with a limit switch at the top position of the ram, and if either is out of position or defective, you will encounter your problem.