I installed the two tone Hella Air Horn that uses an air compressor. I have a wire powering it and my fog lamps. It is very loud., the only thing is I wish it sounded more like the Old truck air horns I.E. the pitch is too high but it gets the job done. I tucked all up and out of the air stream were the "Y" is at the right front between the rails. It was a fun install.
Bill Witz 84 Westy