WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The starting system consists of the following components:
Starter motor
Starter switch, part of the ignition switch
Digital transmission range (DTR) sensor
Starter motor relay
Starter solenoid
Starter drive
Fig 1: Identifying Starter Motor (6.0L Diesel Engine)