Current is distributed to terminals 85 and 30 of the horn relay through CKT 1540 from the 15 Amp Horn fuse. When the horn switch is pressed terminal 86 of the horn relay is grounded through CKT 28. The switch side of the relay then closes which allows current to flow through terminal 87 of the relay. Current then flows through CKT 29 to the horn allowing the horn to sound. The horn itself is grounded through CKT 150.