The Ford F-150, Ford's most popular truck, uses four total bulbs for the turn signals. Two are up front and two are in the back. The front turn signal bulb also doubles as the parking lamp, while the rear turn signal doubles as the brake light, sidemarker and running taillight. Replacing any of these bulbs will only take a few minutes with a minimal amount of tools. While these instructions are for the F-150, the same procedure applies to the Ranger and Super Duty trucks.
Open the hood to access the light assembly. Locate the screw at the top of the lamp assembly.
Unscrew the screw with a Phillips screwdriver. Disengage the lamp assembly by pulling it straight out. The assembly has a snap fit that will release the assembly.
Unscrew the socket in the back counterclockwise to pull it out. This will expose the bulb.
Pull the bulb out of the socket by hand. Replace with the new bulb. Push it in until it locks in place.
Push the assembly back onto the front of the truck. The assembly will snap in place. Insert and tighten the screw with a Phillip screwdriver.
Close the hood. Test the signal to ensure it is working correctly.
Open the tailgate and allow it to lie all the way down. This will expose the two bolts on the side of the taillight assembly.
Unbolt the two bolts with a socket wrench. This will release the taillight assembly. Pull the taillight assembly away from the back of the truck.
Turn the top socket counterclockwise to release it from the assembly. This will expose the bulb.
Pull the bulb out of the socket and replace it with a new bulb. Screw the socket clockwise into the back of the assembly. The socket will lock in place.
Push the taillight assembly back onto the back of the truck. Tighten the bolts on the side of the assembly with a socket wrench.
Close the tailgate. Test the turn signal bulbs to ensure they are functioning correctly.
