Engine ON. Open and close the entry door. WATCH the underside orange step light. IF the light comes ON when door is opened and goes OFF when closed, your 12 volt power and connections and door switch are OK. If this is correct, Take a hammer and while someone opens and closes the entry door, engine ON, whack on the step motor as you open and close. If after a few minutes the motor activates---Replace the Motor. If it does NOT, replace the Motor:B Doug