What vehicle is this and what tower does it have?
Regarding the plastic switch for the defender style vehicles:
If the switch gets screwed in too far, it can gall the plastic and prevent the center button from coming out rendering the switch inoperative.
Also a lot of the threads in the plastic switches are of poor quality.
I always chase the threads with a dye before installing.
The length of threads you screw in is how the switch is adjusted and there should be a nut to lock the switch in place.
It's plastic, so take care not to over tighten.
Uncle "Richard" Douglas has a Land Rover with big wheels that never gets stuck... until he breaks something so it won't go. Uncle Douglas always breaks something. - Anna Crowther at the Conclave 2012 (AKA Carburetor Neck)
"What's with this death wobble, Uncle Douglas, I can't keep it in 1 lane?"
UD: "Just Power through it man!"