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.
When the fog lamp switch is engaged, the high beams are not illuminated, and the exterior lamps are on, the lighting control module (LCM) energizes the fog lamp relay and power is supplied to the fog lamps.