69 Barracuda Horn button missing.

Usually an aftermarket steering wheel with have the horn assembly included, and all you have to do is connect the one wire that comes through the column to the horn contact ring! It usually clips on! If by chance someone has pulled the wire back through the cumin to use the dash mounted button, they almost surely clipped it at the steering column plug! A wiring diagram should spell out the color of the wire to look for and the location of the wire in the column plug! Geof