With Engine ON, open and close the entry door. IF the underneath orange step light comes on and off when the door is opened and closed, your wiring and fuses(so far) are OK. The most COMMON fault if the previous checks out is a dead armature on the motor. With the engine running, open and close the door and HIT the motor with a hammer. Do this until the step extends. Once the step is extended, you can easily replace the motor. Odds are the step will operate now, but with a dead armature spot will fail again. Replace the motor while the steps are extended. Doug
PS, the steps assbly's NEVER need any type cover. The controls and motor are sealed from the elements.