None if it is the original horn. Turn the wheel all the way and hold your tongue "just right". There is a bolt at the top of the mount that holds it on and a couple slip on connectors. At this point some have purchased both a high and low horn and mounted them there. Some use additional relays, some don't.
And some of us have even gone further and replaced the horn with a set of dual air-horns. You have to use a relay with these babys for sure.
