Principles of Operation
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The stoplamps are powered directly from the stoplamp switch, not from the lighting control module (LCM).
The stoplamps are supplied voltage from the stoplamp switch. When the brake pedal is applied, the internal switch closes and voltage is supplied directly to the high mounted stoplamp and the multifunction switch (which then routes the voltage to the rear stoplamps).