High Beam Indicator
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster provides a ground for the high beam indicator. The multifunction switch provides a switched power source to the instrument cluster to illuminate the high beam indicator when in the high beam position. When the high beams are activated, the multifunction switch sends a power signal to the instrument cluster and illuminates the high beam indicator.