You should be under warranty for your 2018 motorhome? I doubt the control box got wet inside. They have those controls very well sealed and I have never had a control box get water intrusion on a Kwikee step. What WILL cause your problem is the door magnet or Pin switch whichever you have, the brown wire (1) that goes from the Door switch to the control box. IF that connection is not weather tight and water/corrosion gets to it, That may complete the ground signal to open and close causing the step to extend and retract. This connection is underneath at the step wire connections and NOT inside a sealed water tight area. The step door magnet/pin switch is a normally OPEN, which means NO ground signal is sent to open the step. IF you get water/corrosion intrusion, that would complete the ground signal and the step will extend, then retract as the corrosion is not a complete ground circuit. Doug
