The horn ring is held onto the steering wheel by a round plastic piece with three prongs, the three prongs connect to the horn contacts in the steering wheel.
Under the steering wheel is the turn signal switch. It contains the connections for the directional blinkers and two spring loaded connections to touch the horn contacts on the rear of the steering wheel.
The spring connectors can be seen here on the right side, the two pieces sticking up
In my case, the spring connectors on the turn signal switch were destroyed. One was broken off and missing, while the other had fallen off.
There are two wires which connect to the spring connectors and run down the steering column to a 6-port connector under the dash. One is yellow, which carries the 12Vdc and one is blue with a yellow stripe which runs to the horns. The other wires on the 6-port connector are for the directonal indicators.
At this time I have not found any fuse inline with the horn mechanism, but jumping the yellow and the blue/yellow ports on the plug under the dash gets the horn to sound. Extending these up to the steering wheel produces the same result.
I need to buy a new turn signal switch and steering wheel to resolve my problem. It appears that the steering wheel cracked, as usual - which caused the screw holding the slip rings on the back of the steering wheel to become dislodged, and shifted - which closed the circuit and caused the horn to blow. They cut the yellow wire coming from the 6 port connector under the dash to turn the horn off.
Basically the turn signal mechanism is fine, just the entire mechanical assembly under the steering wheel and the horn ring are destroyed. I don't believe the steering wheel can be repaired in a manner which will allow the slip rings to function properly.
New horn ring - $3
New Steering Wheel - $180
New Turn Signal Switch - $45
Total to repair the broken horn - $228