Hi Jim, it draws 18 amps and comes with a relay. I connected sufficiently thick cable to the battery and the correct terminal on the relay via a 20 amp fuse. Then used the two wires from the original horn to switch the relay. Connected a lead from the switched power of the relay to the horn and grounded the negative horn connection.You just need to find if your bike uses a positive switched horn supply or negative. The silverwing is negative.
Full instruction come with the horn but you might need a magnifying glass to read them, I did. Something to do with not wearing boxing gloves to bed when I was a lad apparently.
Bob
