Demand Lighting
WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The battery saver relay provides power to the demand lamps. The demand lamp switch, which when activated, provides power to the selected demand lamp. The battery saver relay is energized anytime the IC is not in sleep mode.