The horn did work before you changed the wheel? You kept your wires straight through the new plates, and the plates are pointed the right direction up? I usually have the other problem, in that the horn wants to be on all the time. In that case, one of the guys here on the board recommended that you cover the inside of the horn button with black electrical tape.
The horn did work before starting. The problem is, we got everything done, and the horn wouldnt go off, until we actually depressed the horn button, and MADE contact. Then it stopped.
The install kit called out by Grant is a one wire kit, and I think we need a 2 wire kit, as there are 2 posts, that rode on 2 separate tracks on the back of the old wheel. These were insulated from each other, for whatever reason. My hunch is, it has something to do with the tilt-a-way column.
All of the pictures on the Grant web site are the same picture, so there is no way to really tell whats what.
Hopefully someone can can set me straight, because I just know I am missing something.