Thanks folks.
I spent a couple of hours on it yesterday. Took the steering wheel and column covers off, all looked good. I pulled the horn fuze and found it blown, yet the horn still blew along with the signal. I pulled the relay out, no change. So finally I just unplugged the horn and ran a new circuit to a switch on the dash.
I did find a big bundle of tape and wires running next to the fender by the air box on the right side, but I didn't have the time or patience to tear into it. God knows what else is going on in that mess.....
