On my Winnebago View, the two brass contact buttons on the coach door are the actuation for the door lock. On mine, it works off the Sprinter key fob for the cab (c class).
You can clean them with scotchbrite or very fine sandpaper or even a pencil eraser. They can be adjusted by removing the two phillips screws and pulling out the contact mechanism and screwing the nylon stop nuts in or out to allow more or less brass button protrusion. Don't cross up the wires or install the contact upside down as this will reverse the polarity and make the lock work opposite what it should.
Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.