A headlight is a crucial component of a vehicle’s lighting system. It is attached to the front of a vehicle to illuminate the road ahead at nighttime or during severe weather conditions. As a general rule, headlights come in pairs to ensure maximum visibility and mark the shape of the vehicle.

Most headlights are maintenance-free parts that do not require regular checks or inspection. However, you should visually inspect your headlights for damage and wear from time to time to prevent their unexpected failure. 

Signs your headlights are failing 

  • Both headlights or one of them do not operate
  • Discolored headlight lenses 
  • You can’t adjust the headlights
  • Water or dust inside the lights

Headlight troubleshooting and maintenance

  • Burnt out bulbs are the most common headlight failures. In most cases, fixing this problem involves replacing bad bulbs without replacing the entire headlight assemblies.
  • You should replace bulbs in both headlights at the same time.
  • Some headlights come with just one bulb for the low and high beams, while others can be equipped with separate bulbs.
  • The headlights should be properly aimed. Make sure to check the adjustment after replacing the bulbs.
  • If you have headlights with separate low-beam and high-beam bulbs, the first one should be located outward or above the high-beam counterpart.
  • Depending on the headlights, they can come with halogen or HID (high-intensity discharge) or xenon bulbs. The latter ones are usually very expensive.
  • Failures of the high-beam switch can affect headlight operation.