Quick question on horns...

Hello. Car is 68 Barracuda. I put a new steering column in. Everything is hooked up right. Problem is my horns. Before I put the steering wheel on, I connected the two
contacts with the wire, and the horns worked, they honked.

Then I put the steering wheel on, and connected the wire and they don't honk. All I hear is the horn relay making a "clicking" noise. Everything is grounded properly. I hooked up an electrical tester, the power probe ll, which is quite a dandy little tool where you hook it up to the battery and can add positive or negative supply. I tested the horns themselves, and they don't work.

What could have caused this? Why do all of a sudden do my horns not work? Could I have blown them somehow? Do they "go out" after a while, kind of like a light bulb? I tested another set of horns that I took out of my Dart, and only one horn works, the other doesn't... Why????????