Ford Explorer: Horn / Description and Operation - Horn - System Operation and Component Description

System Operation

System Diagram

Horn Operation

The horn switch uses sets of contacts separated by springs. The lower set is connected to ground and the upper set is connected to the horn signal circuit. When the driver airbag is pressed, it pushes down on the upper set of contacts, collapsing the springs and allowing the contacts to touch. When the contacts touch, it completes the circuit and provides a ground signal through the clockspring to the BCM horn input. The BCM then grounds the integrated horn relay coil in the BCM-C to energize the non-serviceable relay. When energized, the horn relay provides voltage to the horn, enabling the horn to sound.