i'm running a momo champion wheel and my horn currently doesn't work.i think you need a horn ring or "button" of sorts.tckline racing sells it.i've heard of other ways of wiring it up,but haven't got around to look at it.if you do figure it out without getting the ring or "button",please let me know as well.my finger is getting tired from all the ppl cutting me off.i need a horn.....