The 2003 base model Ford F-350 came equipped with a 5.4-liter V-8 engine. There were four other engine options for the 2003 F-350, including a 6.0-liter diesel engine. The 2003 F-350 has an ignition lock cylinder, connected to the ignition switch in the steering column. The ignition lock cylinder is usually replaced when it will not start the truck, or if the key tumblers wear out and the cylinder malfunctions. Replacing the lock cylinder is somewhat easy, is capable of completion within an hour depending on your mechanical ability.
Access
Open the hood of the F-350. Disconnect the negative battery cable from the primary battery and the auxiliary battery, if so equipped, using a ratchet and socket set. Open the driver's door of the F-350. Remove the three mounting screws for the bottom steering column cover, with a Philips screwdriver. Remove the bottom cover from the steering column.
Removal
Turn the ignition key to the "Run" position. Push the locking pin up from the bottom of the lock cylinder, with a small punch awl or screwdriver tip. Pull the ignition cylinder out of the steering column once it releases.
Installation
Turn the key on the new cylinder to the "Run" position. Insert the cylinder into the steering column. Inspect the connection at the inner end of the cylinder, to ensure the ignition lock cylinder is aligned properly with the interlocking washer. Turn the key to the "Off" position. Turn the key a couple of times to the "Run" then the "Off" position to ensure it is aligned properly. Remove the switch and install it again if you have any alignment issues. Reinstall the bottom shroud against the lower steering column. Insert the three mounting screws and tighten them snug with a Phillips screwdriver.
Testing
Install the negative battery cable onto the primary and auxiliary batteries, if so equipped. Tighten the battery cables snug with a ratchet and socket. Turn the engine of the truck on and off twice, to make sure the new ignition cylinder is working properly. Remove or adjust the cylinder if your truck is having trouble starting. Make sure you wait until the "Wait to Start" light goes off in the dashboard, before attempting to start the engine of the truck.
