I used the same harness as greenpus. I mounted the relay under the left side cover.I Like the heavy plastic tube (protective sheath),used the pull ties to fasten to the underside of the frame. I mounted the the horn under the rectifier useing a"P" ring from Kury
. You can see the horn in my sig pic. It'up high enough the fender protects it,& it's facing forward. If you send me a PM with an email address I can send you pictures if you like.