Well, found the issue... The horn wire was corroded and broken in the harness. But, here is the kicker, it was the only wire like that. This would have never happened if one, the wiring harness was properly protected, wires where exposed, and two if the wire had not broken away from a retainer and were rubbing against the inner side of the fender.
Attached is a picture of the wire harness in question after I pulled it out for repair, sorry no before and after pictures. Also attached is a picture of the corroded wire.
FYI, the horn now works after repairing the broken wire. Also, the harness is completely covered and protected and has been restrained so it will not rub against the fender any longer.
http://www.disorder.com/gallery/d/10722-2/img_0520.jpg
http://www.disorder.com/gallery/d/10726-1/img_0526.jpg