Hey 93 DC,
Check under your horn pad. If I remember right the contact is made on a copper plate or foil like arrangement. I managed to deform mine in a panic stop situation and it quit working. Took several tries to get it right but I was able to reshape things and get it to work. It went off a few times on it's own and even stuck once until I got i right. That's an ugly thing when you're under the hood! It may be worth a shot.
Good luck, Bob