Horn parts help

Hello everyone! Got almost everything ironed out with the lights. Everything works except the cluster turn indicator. Anyway, the new turn signal switch has a horn contact. Horn started blowing when I installed wheel. Looks like I'm missing something? Car is a 74 Duster. I checked in the steering column section of the downloaded manual. Don't show in detail( that area) . Any ideas what I need ? I would hate to unplug it all...... in advance, Thanks!