[jwhotrod]

unless I misunderstand, you have a horn power wire that starts in the fuse block and you are confused as to where it goes. That power wire goes to your horn relay. the green wire from your column also goes to that relay. from the relay there will be a wire that goes to your horn. The wire from the column switches ground thru the horn button that completes the control circuit in the relay telling it to send power to the horn. the reason it is done this way is the wire going up into the column is not heavy enough to carry the amperage the horn requires to operate.