The horn system starts at the fuse block with the horn/dome fuse. The circuit goes from the fuse block to the horn relay in the Underhood convenience center. At the horn relay, the circuit splits. One branch of the circuit goes through the relay coil to the horn switch in the steering column. The other branch of the circuit goes through the relay contacts to the horn.

When closed, the horn switch provides a ground path for the horn relay coil. The current flows into the relay coil, closing the contacts which allows the horn to sound. For diagnosis of the horn system, refer to Starting System Check .