Like most vehicles, the 2005 Mazda 3 Hatchback has a high-beam and a low-beam headlight. These bulbs are drastically different, as is the procedure for replacing them. Some higher-end models, such as the GT or SP23, are equipped with xenon headlights. These headlights are not owner-serviceable. If your Mazda 3 Hatchback is equipped with xenon lights, see your Mazda dealer for replacement.
Turn the headlight switch and engine off. Apply the parking brake lever and open the hood.
Locate and remove the three screws on the plastic cover directly above the headlight assembly.
Remove the plastic cover above the headlight assembly. This will allow you access to the rear of the assembly.
Locate the low-beam headlight socket (this is the socket closest to the fender, on both the driver and passenger side). Unplug the connection behind the socket.
Pull the rubber sealing cover straight off. Push the socket retaining spring out to disengage the bulb socket. Pull the bulb socket straight away from the assembly.
Insert the replacement bulb. Push the retaining spring up to secure the bulb socket. Reattach the rubber sealing cover and reconnect the electrical connector.
Place the plastic cover back on its mount. Tighten the three Phillips screws.
Turn off the headlight switch and engine. Apply the parking brake lever and open the hood.
Locate and remove the three Phillips screws on the plastic cover directly above the headlight assembly.
Remove the plastic cover above the headlight assembly. This will allow you access to the rear of the assembly.
Turn the high-beam socket counterclockwise to unhook it from the assembly (the high-beam bulb is the bulb closest to the center of the vehicle). Pull the socket out of the assembly.
Press the plastic tab on the socket's electrical connection; pull the connector away from the socket. Discard the old bulb and socket.
Connect the electrical connection to the replacement bulb socket. Insert the replacement socket into the assembly; turn it clockwise to lock it.
Replace the plastic cover. Tighten the three Phillips screws.
