Aim headlights to get the best visibility for night driving, without blinding the oncoming drivers. Proper vision is one of the keys to driving safety. Headlight adjustments can be compromised by a number of things. Often the installation of new lamp or bulb causes a slightly skewed aim. Certainly the installation of a lift-kit demands a realignment of the headlights. Line up your headlight aim for successful night time travel.
Time the job so that it's dark enough to see the headlight's glow clearly. Begin working at around twilight.
Park the car on a flat surface facing a wall or garage door. The parking surface must be long enough to allow you to park the front of vehicle 7.5 m (25 feet) away from the wall or door, but park the front of the vehicle up close to the wall for the initial procedure.
Mark a centre line on the wall. Extend a metre rule from the bonnet ornament, or centre line on the bonnet, to the wall or door. Make a vertical line on the wall with masking tape to mark the vehicle centre.
Take measurements for reference marks. Measure from the ground to the centre of one headlight. Mark the wall 5 cm (2 inches) below that measurement with a horizontal stripe of tape that's as wide as the vehicle. Place a metre rule vertically in the centre of front grill. Use the bonnet ornament for a guide. Measure from the centre of a low beam headlight to the centre of the metre rule. Measure that distance from the vertical centre tape along the horizontal tape stripe. Mark the distance with small vertical strips of tape that cross the horizontal tape on both sides of the centre line. Your wall marks will look similar to this: (----+-------|------+----)
Back up the car in a straight line until the headlights are 7.5 m (25 feet) from the wall. Use a tape measure to mark the distance accurately. Be sure the drive or parking surface does not slope up or down.
Turn the low beam headlights on. Notice the glow from each lamp is lower on the left side than on the right. The flat line at the upper left of the glow is called the cut-off.
Adjust the vertical aim of the beams. Use the vertical set screw over the centre of the lamp to set the cut-off of each beam level with the horizontal tape line.
Adjust the horizontal aim. Use the horizontal adjustment screw, off to the outside of the lamp, to line up the angled slope coming up from the cut-off with the vertical side marks.
Adjust the high beams on vehicles using a four lamp system. Leave the vehicle in the exact spot where the low beams were adjusted. Switch on the high beams. The glow should fall below the horizontal tape line, and be evenly spaced between the low beam markers. Use the horizontal and vertical set screws as needed to position the high beams as such.
If you are unable to find an adequate surface next to a wall for this job, most garages will adjust your headlights for a very reasonable fee.