The PO added electric horns because the Hadley Air Horns must not have been working. I did a systems diagnosis, dismantled the air horns themselves, and they were full of debris. I blew them out, and reassembled. I then checked the electric, and for whatever reason the solenoid for the air horn was disconnected. I reconnected it, tested the system. Verified resistance, current, and voltage to ensure it was not a preventative measure. It looks like someone was working on the rig and just forgot to reconnect it. So I have fully functioning air horns, and electric horns. When I press the horn I get a loud blaring from a total of four horns. Two electric and two air. It scares the bejoobers out of people who try to get too close to my rig. And truth be told, I like it, because their reaction is to move away.
1994 36' Classic Diesel Pusher