[Daves55Sedan]

Constant horn blowing usually means that your horn button wire insulation inside the steering tube has worn off and is now in contact with ground (which completes the circuit, the same as if you pushed down on the horn ring).
Take note that there should be three wires going to the horn relay. The middle terminal gets the yellow wire (that is the power wire to the relay coil). The right side terminal should have a blue-yellow wire (that is an extension of your horn button wire which is ground and it completes the circuit, activating the coil). That middle terminal is internally jumpered to the relay contact input terminal. The left terminal of the relay is the relay contact output terminal. That wire goes to your horns.
Check all your wiring connections to the relay to see if they are connected correctly. Doesn't look like it to me.
Another thing that can happen is if you have taken the mechanism apart on the backside of the horn ring and accidentally put the nylon spacers in backward, that might cause problems also.
Make sure the collar of your horn button wire is all the way down on the end of the steering shaft. If the collar is sticking up, it pushes the horn button wire up closer to the back of the horn ring. You don't want that. This could be evidence of the horn button wire twisted inside the steering shaft. If it is doing this, replace the horn wire with a new one. they are still available new from the repro parts suppliers.
The horn button wire is NOT supposed to twist inside the steering shaft when you make turns. Thats why they designed it with that collar and little spring at the top, just to hold it loosely above the top of the shaft, but the wire should remain stationary inside the steering shaft.