I have a Dometic model RM3962. I installed 12v fin fans on the unit and wanted to wire them to the light. I popped the fixture off and found no room for the connections and ended up running the wires through the drain tube. My problem is re-attaching the fixture. The white fastener is now deformed and won't make a tight fit. I don't know what this piece is called and don't know where to get it. Bestow your knowledge on me please.