Proper Headlight Adjustmentby Lee Morgan
If you've ever been driving down the road and been blinded by an oncoming car's headlights, it doesn't necessarily mean the car's high beam lights were on. Misaligned low-beam headlights can appear as brighter high beam lights if they are not positioned correctly. You've probably seen evidence of this when you flash your lights at such a car and they surprise you with even brighter lights. Prevent this safety hazard by making sure your headlights are properly adjusted before you go back on the road.
Use a white wall or garage door to begin the process. The area in front of this wall or door must be flat and level. Pull your car up as close as you can to the wall and turn your headlights on low beam. Use masking tape to carefully mark a line on the wall that runs horizontally through the brightest spot of light your headlights leaves on the wall. This tape should run the entire width of your car. Mark the center of the car with another piece of tape, measuring out from the hood ornament. Tear off another strip of masking tape 4 four inches long and place it vertically across the horizontal line at the point where the left light shines brightest. Repeat this for the right side. This measurement will give you a reference point to the height of your actual lamps and will guide you in properly adjusting them later in the process.
Move The Car
In order to get an accurate adjustment, the car must be moved a distance away from the wall. However, if it is not backed up in a straight line, the adjustment can be off dramatically and it may make your lights more out of line than they were to begin with. Make sure your wheels are straight and ease the car back in reverse for 25 feet. Put it in park, turn off the engine and leave your lights on low beam.
Proper Beam Adjustment
Notice where the brightest spots from your low beam lights are now in relation to the markings on the wall. Odds are they are not still lined up perfectly on the cross marks. If they are, you still have a problem. Assuming you are in a place where you drive on the right side of the road, then your lights will need to be aimed slightly below center and off to the right to shine away from oncoming cars slightly. If your low beams are adjusted correctly, the bright spots will appear 2 inches below and to the right of the cross marks on the wall. If they aren't in that position, adjust them by turning the adjustment screws. Locate two adjustment screws on each lamp. The one at the top will move the lamp up and down, and the screw at the bottom will move it left and right. Use a screwdriver to adjust these screws so that the bright spot will line up in the proper space on each side. After you have them lined up, switch to brights and adjust the high beams so that they point barely below the horizontal line on the wall and an equal distance apart from the center line of the car.