Jed,
I was waiting for someone else to throw in their two cents. It sort of isn't that simple. To be proper, the button should operate a horn relay, which is located nearer the horn mounting location and switches battery voltage through much larger wires so your horns are real loud and scare the heck out of old people and dogs. Do a search and you will find lots of info/wiring diagrams. So, it is simple, but not that simple!!
Stuart.
