The headlights in your 2000 Mazda MPV are 9004 halogen headlights. These headlights will need to be replaced when the filament inside of them breaks. Because the MPV's headlights do not have a specific service life, you can try to prevent a sudden failure of your headlights by replacing your headlights every two years as preventative maintenance. Replacement headlights can be purchased from most auto parts stores.
Open the hood and unplug the headlight connector running to the back of the headlights. Squeeze the headlight connector tabs and pull the headlight connector off the headlight.
Pry the dust protector off of the back of the headlight with your fingers.
Pry the spring clip off the back of the headlight.
Pull the headlight straight out of the headlight housing.
Insert the new headlight into the housing and secure it to the headlight housing using the spring clip.
Replace the dust cover and plug the headlight connector back into the headlight. Make sure the headlight clips and locks into place.
