I would check with a test light at the plug and have someone hit the horn and see if you are getting power. If you are it's the horns. Putting voltage to the horns should have made them sound. Double check the ground too.
@340wedge - ok, will check at the plug and report back. When you say check the ground? Which ground?
At the bracket on the rad support? The brackets were previosuly powder coated, so perhaps I should take some of the paint off the bracket where it meets the rad support? But will check the two plugs on the harness first.