Also check the strap(s) on the rag joint on the steering column. The column provides the ground, and if the rag joint was replaced and the straps left off, it insulates the horn contact. Take a test light, clamp it to the + side of the battery, touch the point to the column in the engine compartment above the rag joint and be sure that it lights up. No light = no ground = no horn.
BillL
BillL