Battery voltage is supplied to the coil, and switch of the horn relay #36, in the underhood electrical center. The horn relay coil is energized when circuit 28 is grounded. This may be done through the horn switch on the steering wheel, or through the Body Control Module when the horns are used as an alarm or a signal, for the Universal Theft-Deterrent System. When the horn relay coil is energized the normally open horn relay switch is drawn closed, and battery voltage is supplied to the horn feed circuit 29 through the horn fuse #11.