Rear Blower Motor
WARNING: This page is about a different car, the 2016 Ford Transit-350 HD, 2016 Ford Transit-350, 2016 Ford Transit-250, and 2016 Ford Transit-150. However, it is still accessible from the selected car via links, so may be relevant.
The rear blower motors are variable speed motors that pull air from the vehicle interior and force it through the rear evaporator housing and the rear heater core housing.