Principles of Operation

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The horn relay B+ power and the horn relay switched power are supplied through circuit 1682 (RD/LB). The horn relay is controlled by the horn switch. The horn relay is grounded through the horn switch by circuit 6 (YE/LG). When the horn switch is pressed, the horn relay control circuit 6 (YE/LG) is grounded. The relay is then closed causing B+ voltage to be applied to circuit 1 (DB), sounding the horns.

The horn relay is powered on both the control and controlled sides by circuit 1682 (RD/LB). When the horn switch is pressed, the horn relay control circuit 6 (YE/LG) is grounded through the horn switch. The horn relay is then energized, allowing battery voltage to flow through the horn relay to each horn through circuit 1 (DB), enabling the horns to sound. When the vehicle security system is armed, the smart junction box (SJB) provides a momentary ground to the horn relay control side to indicate the system is armed, and a continuous ground when an intrusion is detected. For additional information on the anti-theft system, refer to ANTI-THEFT - PERIMETER .