The old horn's power connector is just snapped on. I started making a harness using this connector so I wouldn't have to cut the original wires. I abandoned this method when I decided to keep the stock horn in the system. I just tapped the horn voltage for the compressor relay using weather resistant crimp taps. They are different from the regular taps because they contain some kind of clear gel to repel moisture.
I'm a middle aged guy, with a middle school mind.