Do I need to change both headlights at the same time?
This isn’t necessary. However, if you replace the bulbs in a new headlight, then it is better to install new bulbs in the old one as well. Over time, the light intensity of the bulbs decreases and their colour temperature may change, which affects the lighting efficiency. If the headlights have been used for a long time, their lenses may be scratched, and the reflectors slightly fogged, in which case it is better to replace both of them. This will help ensure intense and uniform light beams.
Do I need to disconnect the battery before replacing the headlights?
Yes, before getting down to work, be sure to disconnect the negative terminal from the battery. This is a safety requirement. In addition, disconnecting the terminal prevents software errors that sometimes occur after installing new bulbs.
Why do headlights dim over time?
The most common cause of decreased light intensity in halogen headlights is a cloudy bulb. Usually, it is the result of installation errors. In particular, halogen lamps should not be touched with bare hands: greasy spots left on the bulb surface quickly turn into carbon deposits. This leads to local overheating and affects the light intensity. Over time, xenon bulbs change their colour temperature and also lose their light intensity. In addition to the bulb issues, headlights may become dim due to the reflector fogging or flaking off, a scratched lens, as well as problems with wiring.