The horn wire that runs thru the center of the steering shaft has a woven nylon jacket for protection from wear. You can buy that wire with the special terminals pre-attached at many Ford parts resto suppliers. That wire connects to a wire in the harness that runs to the horn relay "ground" terminal (which completes the circuit when horn button is depressed). The large yellow wire at relay is Battery "Hot" wire and the third wire at the relay runs out to the horns.