Honking horn blows a fuse

I was driving along yesterday and went to honk the horn. I got nothing.

I checked the other horn (the 560SEL has a button to select the horn to use) and again I got nothing.

When I checked the fuse, it was blown. I replaced it, and checked it with horn #2, and everything was fine. When I switched back to horn #1, it blew the fuse again.

I plan to disconnect horn #1, press the horn, and see if the fuse blows, if not I will replace the horn itself.

Now for my questions -

1. Where is the "American" horn? It's the one that get's used when the horn switch has the rear side of the rocker depressed.

2. What to I do next if disconnecting the horn and pressing the horn switch still blows the fuse?

Thanks.