Battery Saver
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 IC provides a ground circuit for the battery saver relay coil. The battery saver relay provides power to the demand lamps. When the ignition switch is switched to the OFF position the battery saver relay remains energized until a predetermined time-out has elapsed and the IC deactivates the battery saver relay.