Ford Expeditions are equipped with halogen headlight bulb inserts, which rest inside the headlamp assemblies. While the halogen bulbs outlast their sealed beam predecessors, the need to replace them at some point still exists. You can purchase replacement halogen insert bulbs at most auto parts stores, mass retailers or your local Ford dealership. Be sure the bulb you purchase is the right style for your model year Expedition. Replacing the bulb should take no more than about 15 minutes.
Shut off the Expedition and turn the headlight switch to the "off" position.
Raise the hood and unbolt the headlamp retaining fasteners, located at the top of the headlamp assembly, using the socket set.
Loosen the vertical bolt located at the back of the headlamp assembly, but do not remove it.
Pull the headlamp assembly forward, by hand, until you can access the rear of it easily.
Pull the headlight bulb socket covers off by hand (if your Expedition has socket covers).
Turn the headlight bulb socket counterclockwise and pull it out of the headlamp assembly. Pull the old bulb out by hand and insert the replacement bulb. Do not touch the glass portion of the replacement bulb with your bare skin.
Reinsert the socket and bulb into the headlamp assembly, align the retaining tabs with the retaining tab slots and turn the socket clockwise until it clicks into place. Reinstall the socket covers, if so equipped.
Push the headlamp assembly back into position and reinstall the two upper retaining fasteners by hand. Tighten those two and the vertical bolt with the socket set. Close the hood and test the headlights before driving the Expedition.
