While cleaning the coils of the Trane XB10, one of the wires (Brown) came off the terminal block. There a number of tabs it coiuld be slipped over, but I'm not sure which one it came off. There are three possible tabs it could fit on each side on the top of the terminal block. 3 on the left and three on the right. Anyone have any idea where that brown wire fits? It is one of three wires, Purple, Black and Brown that come out of the unit in a section of plastic conduit.