Bulbs wear out over time. About every two years, bulbs need to be replaced, even if they are in good condition. This does not apply to halogen bulbs, which are used in headlights and fog lights. They usually last much longer and are replaced if damaged. Bulbs with reduced light output are also identified by black deposits on the glass bulb. Bulbs should only be replaced with bulbs of the same design and with the same characteristics.
Before replacing the lamp, switch off the corresponding consumer.
Warning: Do not touch the lamp glass with bare fingers. The grease from your fingers evaporates and settles on the reflector, impairing its reflectivity. Fingerprints on the glass should be removed with a clean cloth soaked in alcohol.