The starter in your Ford F150 is a small but powerful motor with a solenoid connected to both the battery and engine that turns the engine over. A bad starter won't allow the engine to turn over when you turn the key. If you hear no cranking sound when turning the key and know that the battery/electrical system is good, the starter probably needs replacing. You must disconnect the starter from the battery to remove it from the engine and replace it.
Disconnect the cable from the truck battery's negative terminal. Raise and secure the F150 on jack stands.
Disconnect the wiring from the starter motor solenoid. Remove the hex nut holding the cable to the B+ terminal and remove the cable. Do the same with the cable connected to the S terminal.
Disconnect the starter's ground cable from its lower mounting stud by removing its bolt, then remove the mounting fasteners attaching the starter motor to the engine. The starter has two or three bolts depending on the engine, with the lower bolt being a stud bolt. Remove the starter motor.
Install the new starter motor and torque the mounting fasteners to 18 foot-pounds each. Reconnect the ground cable to the lower mounting stud, then reconnect the wiring to the S and B+ terminals on the solenoid.
Lower the F150, reconnect the negative battery cable and test the starter with the ignition key. Connect a voltmeter or test light to the solenoid's S terminal, and make sure the starter receives voltage at that terminal when the ignition switch is in the on position.
