There are no limit switches on the Schwintek slides or bunks. The controller has a current sensing circuit for each motor. When the current draw reaches a certain amount for 1/2 second, the controller shuts down that motor if the Hall effect sensor shows the motor has stalled and it is near the calculated distance to be traveled. When both motors have shut down due to reaching their max current draw, the controller then re-zeros the counters for the hall effect sensors. This is why you must hold down the extend/retract switch for 3 to 5 seconds. During slide or bunk operation the controller will vary the voltage to a single motor to keep the signals from the hall effect sensors in time.
Bunks will drift down when traveling if the travel pins are not installed. I raise the bunk full up then install the travel pins. Next I lower the bunk until the pins are held firmly in place. To remove the pins raise the bunk fully up holding the switch for 3 to 5 seconds. I have never had a problem with this procedure.
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow