Be aware that the fuse for the horn does also feed other electronics for the engine. Blow the fuse and you affect other things as well. I found that the factory horn even sounds a bit louder when fed by dedicated power direct from the battery through a relay and using heavier 16ga wire rather than the thinner wire the factory uses. I pulled the factory horn wire pair up under the top shelter and used that pair to trigger the relay (the easiest relay trigger source ever) and put an inline fuse just off the battery on the way to the relay. I then also added a 132db low tone Blaster horn from Autozone (they let me test it on the bike in the parking lot before buying it) so I now have 2 horns. The low tone penetrates the cab of cages better than high tones. The factory horn is higher tone than the Blaster so the discord of the two also improves the effectiveness even though the factory horn is not quite as loud.
Both horn brackets are mounted at the factory horn mount point, one angled forward to the right and the other back and to the left. Both horns face down and forward. The Blaster has a coil trumpet.
See some
details with wire diagram HERE in post 2 & 3. also see the relay location in post 1.
I used a 15 amp fuse since I also use this relay to switch to the 15 amp 12 volt socket under the seat. It's wired so either the socket has power
OR the horns, but not both at once. This is possible with a special relay that has pin 87
A for normally off power.