These can include the sealed beam variety (older cars) or, more common today, lamps that incorporate replaceable bulbs. Lamps and bulbs can burn out or be damaged. The actual headlight sockets are regularly exposed to moisture and corrosion because they’re at the nose of the car. Examine the sockets for corrosion or damage.
If only one headlight (or pair of headlights) is out, it could be the fault of the light itself or it could be a wiring issue between the headlights. On most cars and light trucks, the wiring harness is arranged so that it runs down the inside of one fender to the headlight, then across the nose of the car (often following the radiator support) to the opposite headlight. Check the wiring harness for any damage.
Diesel-Electric supplies a wide range of headlamps – contact an outlet near you.
We recommend should you be in doubt on how to change or suspect any issues you take it to an authorised auto dealer or mechanic to make sure all is operating properly.