Okay, so I know both of the horns work. I was able to beeb both of them. My car is a 66, so it is different than yours. I have pretty much tried connecting anything and everything in the horn area, and when it doesnt shoot sparks all over, it never honks the horn...

 

at least you now knwo what it should sound like.
i checked the wiring diagram of a 66 model and they don't have a horn relay.
there's a connector at the firewall, i'd try to unplug and clean it, they're usually rotten.
it should look like the "main disconnect" in the middle of picture:
http://www.hammar.dyndns.org/~djhamm...6/66exter1.jpg

the cable for the horn should be blue/yellow.
From there it goes straight to the horn ring. stays yellow/blue. and a yellow one should join.
So from this if cleaning the connector doesn't help, it's the horn ring or the cable going there.
wiring diagram says the same: the yellow/blue and yellow cable come from the direction signal switch.
So if anyone with a 66 says there should be 2 cables coming from the steering column to the switch then that's what you're missing

Kalli