Headlights are a seldom-considered—but vital—vehicle component, particularly when it comes to driving at night or in inclement weather. Not only do your headlights illuminate the dark roads to help your vehicle stay on the road and avoid collisions, but they also enhance your vehicle’s visibility to other drivers and pedestrians.
Even the best headlights on the finest vehicles in the world won't live up to their true lighting potential if they're not adjusted correctly. Over time, just like your wheels, the bumps and vibrations of rough road miles can shake the beams of your headlights out of alignment. Additionally, the U.S. has no regulations in place that require headlight adjustment from auto manufacturers once headlights have been installed at the factory. This means that even a brand-new vehicle can occasionally roll off the showroom floor with misaligned headlights.
In this article, we're going to look at how to adjust headlights quickly and align them to ensure you're lighting the road ahead properly. Before you begin, you will need a flat, level surface with a clean wall at the end. You can also use an upright piece of plywood in place of a wall. You will need to be able to move your vehicle backwards about 25 – 30 feet in a straight line from your wall surface as well.
Step 1: Ensure your vehicle is level and parked on a flat surface. Getting your vehicle as level as possible means you need to have your fuel tank at least half full to simulate an average load, your tires all need to have proper air pressure, and you should remove any excess or unusual weight from the vehicle.
Step 2: Park the vehicle facing a wall, as close as you can without the vehicle touching it. You’ll also need to ensure that the wall or piece of plywood you park against has enough room that you can back your vehicle up 25 – 30 feet to make your final adjustments.
Step 3: Turn headlights on and mark the center of each headlight beam with a cross of masking or painter’s tape. Use a bubble level to ensure that the tape is level with the ground. For added precision, you can also measure vertically from the ground to each headlight to get its height and apply a corresponding mark on the wall.
Step 4: With your marks applied, move your car backwards in a straight line exactly 25 feet. The DOT standard for headlight alignment states that “a vehicle’s headlights must be at 25 feet away 2.5 inches below the given height of the headlight.”
Step 5: Pop your hood and find the adjustment screws or bolts on your headlights. If you’re having trouble locating them, consult your owner’s manual. One will be for vertical adjustment and the other horizontal.
Step 6: Adjust headlights vertically so that the top edge of the center of your beams is level with the lower edge of the horizontal pieces of tape you’ve applied to the wall. Then adjust horizontally so that the center of your beam falls in the center of the vertical piece of tape applied.
Last, test drive your vehicle on a dark, open road to ensure your visibility is good. By taking the time to properly adjust your headlights, you’ll not only improve your visibility from behind the wheel, but you’ll take steps to make sure your headlights aren’t aimed too high where they have the potential to blind other drivers or pedestrians.
