Horns

Living in the most densely populated state (NJ) in the country I want to change the stock horn. I am considering the Stebel Nautilus air horn. It's a 139 decibels. This thing is F--in LOUD. When that person on the phone or texting drifts into my lane or is at the intersection with that blank look on their face, you know the one that looks right through you. I want to hit the switch and make them think that they are about to be swallowed by a tractor trailer. I went back to my dealer I was told that did not carry it but if I bought it on line they would install it. The problem is the dealer told that I would be taking a big risk of screwing up the electrical system of the bike. The horn runs directly off the battery. The horn button only controls a relay which allows power to flow from the battery. Have any of you long time riders, tinkerers and complete rebuild specialist ever had any issues where an after market thing like a horn caused other problems on your bike?