Headlights serve the important function of alerting oncoming traffic to the vehicle's presence, but also allow the driver to observe obstacles in the roadway with enough time to avoid them. Unlike most other automotive components, headlights cannot just be bolted into place and expected to work properly. They must be adjusted, because headlight which illuminate too close the vehicle or into the sky are of little value. Fortunately, adjusting headlights is a fairly simple task.
Adjusting the Headlights
Automobile headlights must be adjusted on a relatively level surface, since a level surface is most often where the vehicle is operated. Therefore, park the vehicle on a level surface with the front of the vehicle approximately 10 feet away from a dark wall or board. The board or wall should be at a right-angled to the centre of the car so that the headlights are not adjusted too far to one direction. Find the location on the board or wall which approximates the centre of the car, then draw a vertical line down the length of the wall at this location, or use a piece of masking tape.
When a car is parked, it is not uncommon for the vehicle's weight to be resting unevenly on the frame. It is important that the vehicle rest on its frame evenly before adjusting the headlights, so bounce the car on its suspension a few time to allow it to settle.
A horizontal line must be drawn through the vertical line on the board or wall, which will represent the centre of the headlight lenses. Measure the distance between the ground and the centre of the headlights, then draw the horizontal line at this distance. Finally, measure the distance between the centre of each headlight and the centre of the vehicle, then mark an "X" on the horizontal line for each of the two headlights at this distance.
Headlight designs vary, but surround the lens of each headlight are several adjusting screws. The headlight assembly must be disassembled until these screws can be accessed. Turn the high-beams on, then turn each headlight's adjusting screws until the centre of each beam shines onto the "X" marks of the horizontal line. Bounce the vehicle one more time and, if necessary, make any final adjustments to the lights until their beams centre on the horizontal line.
- "Auto Repair For Dummies;" Deanna Sclar; 2008
- "Dare To Repair Your Car!;" Julie Sussman and Stephanie Glakas-Tenet; 2005