Right and Left Turn Indicator
WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, and 2005 Ford E450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The right and left turn indicators illuminate when the multifunction switch is in either turn signal position (or the hazard lamps position) and sends a voltage signal to the instrument cluster.