I hate to get into this so late but to hopefully answer your question, in 1999 Kwikee changed the whole system. The three biggies were the controller, for instance the new one had the last out feature and the old colored ones did not; they changed motors, several were tried and there are several different lift motors in about five years; the third biggie is they changed the magnetic door switch from normally closed(door open) to normally open(door open).
I would guess that you had a pre-2000 system and while it may look the same it isn't. When you told your supplier you had a 2000 model MoHo the supplier didn't ask for the number of the controller and sell you the door switch.
This happens a lot with anything like a motorhome whose manufactures buy individual components from outside vendors and don't make them in shop. Monaco may have bought more than they needed for the 1999 production year and instead of sending the old style to surplus used them until the old model was exhausted and you ended up with a brand new out of production model.