Changing out the high and low beam bulbs in the Mazda 6 is more time-consuming and more difficult than in other cars. The process requires either moving the coolant reservoir or removing the front-wheel splash guard, depending on which bulb you are replacing.
Mazda recommends letting a dealer replace the headlights, but you can do it yourself with a little time and patience. Xenon or HID headlight bulbs are not serviceable; see your dealer for premium headlight replacement.
Turn off the headlights and engine.
Move aside the engine coolant reservoir. To access the high-beam bulbs on the Mazda 6 passenger side, you must move the reservoir. Remove the two bolts securing the reservoir and position it out of the way. Don't disconnect the hoses.
If you are only replacing the driver's side high-beam bulb, you do not need to remove the reservoir.
Disconnect the bulb connection. Press the tab on the bulb connector; pull the connector down to unhook it from the bulb socket.
Remove the bulb socket. Turn it counterclockwise and pull it out.
Remove the old bulb from the socket (pull straight out) and install the new bulb. Do not touch the glass part of the new bulb. Reinsert the bulb socket. Turn it clockwise to lock it, and then reattach the electrical connector.
Move the coolant reservoir back into position and tighten the bolts.
Turn your steering wheel all the way to the right if replacing the driver's side low-beam bulb. Turn it all the way to the left if replacing the low-beam bulb on the passenger side.
Turn off your engine and headlights.
Remove the five Phillips-head screw-retainers from in front of the wheel (on the splash guard). Peel the splash guard back to access the low-beam bulb.
Turn the plastic protective cover counterclockwise to remove it.
Disconnect the electrical connection. Press the tab on the connector and pull straight out to disconnect it from the socket.
Unhook the retaining clamp and remove the bulb socket. The low-beam bulb is secured with a wire clamp. Unhook it and pull it back. Pull the bulb socket from its mount.
Remove the old bulb from the socket and install the new one. Do not touch the glass. Replace the bulb socket and reconnect the retaining clamp.
Reconnect the electrical connection and replace the protective cover.
Push the splash guard back in place and replace the retaining screws.
If you accidentally touch the glass part of the bulb, wipe it carefully with a small amount of rubbing alcohol.