Principles of Operation
WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
The horn switch is incorporated within the driver air bag module. When the switch is pressed, ground is supplied through the clockspring from the vehicle harness. The horn relay is then energized, supplying voltage to the horn enabling the horn to sound. The horn relay is located in the battery junction box (BJB).