Here's How To Adjust Your Headlights (And How To Know If They're Too High)

Yes, misaligned headlights are a menace, and yes, you can adjust them yourself. It's actually a straightforward DIY job and will save you a trip to the shop. All it takes is a screwdriver and some masking tape. The first step is preparing your car to get an accurate reading. Park on a perfectly level surface, make sure your tires are at the manufacturer's recommended pressure, and try to have about a half-full tank of gas. It's also a good idea to unload any unusually heavy cargo from your trunk.

Next, you need a flat, vertical surface like a garage door. Pull your car up as close as you can, turn on your low beams, and mark the center of each beam's brightest point on the wall with a piece of tape, creating two crosses. Now, back your car up in a straight line until it's exactly 25 feet away from the wall – though it's a good idea to check your owner's manual, as it might suggest a different distance.

Next, pop the hood to find the adjustment screws. They're usually on the top or back of the headlight assembly, and you'll typically see one for vertical aim and another for horizontal. Some cars, like many GM vehicles, might hide the vertical adjuster on the bottom, requiring access through a specific cutout. Cover one headlight, and with a screwdriver, turn the screws to aim the other. The goal is to have the top of the most intense part of the beam hit at or just below the horizontal tape line, and the brightest part of the beam should be slightly to the right of the vertical tape line. Repeat for the other side, and you're done.

The most obvious sign your headlights are aimed too high is social feedback. If a lot of oncoming drivers are flashing their brights at you, then it's just them letting you know that your headlights are blinding them. This is dangerous because it can cause temporary blindness for other drivers, creating a massive risk for everyone on the road – a problem only exacerbated by how bright modern headlights have become.

The issue is that your headlights have been knocked out of alignment, pointing up at other cars instead of down at the road. This can happen for a bunch of reasons. A minor collision or even hitting a big pothole can be enough to jar them out of place. It can also happen over time as your car's suspension sags with age, or if you frequently load up the trunk with heavy gear or tow over capacity, which points the nose of the car upwards. Sometimes, improperly fitted aftermarket headlights also cause problems.

Another telltale sign is an uneven beam pattern on the road. Your headlights should create a clear and consistent field of light. If you notice one beam is shooting significantly higher than the other or there are weird dark spots in your field of vision, something is off. While pointing too high is the most common complaint, other misalignments are also a problem. If you feel like you can't see far enough ahead, there's a good chance your headlights are aimed too low. This is dangerous, too, because it shortens your reaction time to hazards in the road. You might also notice an uneven beam pattern on the road, where one light is clearly higher or lower than the other. Any of these signs means it's time to get your screwdriver and tape ready.