Most headlight adjustments take 15 minutes and need only a screwdriver

You can adjust most headlights by turning two screws on the back of the headlight housing — one moves the beam up and down, the other moves it left and right. The screws are usually accessible from inside the engine bay without removing the headlight itself. On some vehicles, especially newer ones, the adjustment screws are behind a panel you'll need to remove first, but the principle is the same. If your headlights point too high, too low, or off to one side, this is a task you can handle with basic tools and about 15 minutes per headlight.

The reason to adjust them yourself is straightforward: a shop visit costs $50 to $150 per headlight, and the adjustment itself is one of the cheapest fixes in vehicle maintenance. You need to know what you're adjusting toward, though — aiming them at a wall or garage door tells you whether they're level, but aiming them correctly means understanding what "correct" looks like on the road.

Key Takeaways

  • Headlight adjustment screws are located on the back of the headlight housing and are usually accessible from the engine bay without removing the light itself.
  • The vertical screw controls up-and-down aim, and the horizontal screw controls left-and-right aim; turning each one a quarter turn produces a visible change in beam position.
  • Proper aim means the beam's brightest spot hits the road 25 to 50 feet ahead of your vehicle and slightly below the horizontal centerline of the headlight.
  • You'll need a Phillips or flathead screwdriver (depending on your vehicle), a level surface, and a wall or garage door at least 25 feet away to check your work.
  • If you cannot locate the adjustment screws or your headlights are sealed units, the headlight assembly itself may need replacement rather than adjustment.

Locate the adjustment screws on your headlight housing

Open your hood and look at the back of the headlight assembly you want to adjust. You should see two screws protruding from the housing — one pointing roughly upward and one pointing roughly sideways. These are your adjustment screws. On some vehicles they're obvious; on others they're behind a plastic cover or trim panel that snaps or bolts off. Check your owner's manual for the exact location on your model, as placement varies widely between manufacturers.

If you see no screws at all, your headlights may be sealed units that cannot be adjusted — some modern vehicles use this design. In that case, the entire headlight assembly must be replaced if the aim is wrong. If you find the screws but they're very tight or corroded, explore penetrating oil and wait 10 minutes before attempting to turn them; forcing a stuck screw can strip it.

Set up a test surface and measure the current beam position

Park your vehicle on level ground facing a garage door, wall, or other flat vertical surface at least 25 feet away. Turn on your low-beam headlights and look at where the beam hits the wall. You should see a distinct bright spot or pattern. Mark the center of that bright spot with tape or a marker so you can see whether your adjustments move it.

The correct position for low-beam headlights is roughly horizontal or slightly below the horizontal centerline of the headlight itself. The brightest part of the beam should hit the wall at or just below the height of your headlights. If the beam is pointing significantly higher than that, your headlights are too high and will blind oncoming drivers. If it's pointing lower, you're not lighting the road far enough ahead.

Adjust the vertical aim with the up-and-down screw

Locate the screw that points upward or downward from the back of the headlight housing — this is your vertical adjustment. Using the appropriate screwdriver (Phillips or flathead, depending on your vehicle), turn the screw clockwise to raise the beam or counterclockwise to lower it. Make small adjustments: a quarter turn usually moves the beam noticeably, so start there and check the wall again before making another adjustment.

After each quarter turn, step back and look at where the beam hits the wall. You're aiming for the brightest spot to be at or just slightly below the horizontal centerline of the headlight. Once the vertical aim looks correct, move to the horizontal adjustment. Do not over-tighten the screw — it should turn smoothly and stop naturally; forcing it can damage the adjustment mechanism.

Adjust the horizontal aim with the left-and-right screw

The second screw, which points sideways from the headlight housing, controls left-and-right aim. Turn it clockwise or counterclockwise to move the beam toward the center of the wall. Again, use quarter-turn increments and check the wall after each adjustment. The beam should be centered on the wall, not drifting to one side.

On the road, proper horizontal aim means the beam lights the center of your lane and slightly into the right shoulder, without pointing into the left lane where it would blind oncoming traffic. The wall test gives you a rough check; the real validation happens on a dark road where you can see how far ahead the beam reaches and whether it's symmetric.

Test both headlights and verify they're even

Once you've adjusted the first headlight, repeat the process on the second one. The two beams should hit the wall at the same height and in the same horizontal position. If one is noticeably higher or lower than the other, your vehicle will pull to one side at night or create an uneven lighting pattern that looks wrong and reduces visibility.

After adjusting both, turn on your headlights and step back to view them together. The beams should look symmetrical — same brightness, same position, same shape. If one looks dimmer than the other, the bulb may be failing rather than the aim being wrong; that's a separate issue. Once you're satisfied with the wall test, take a short drive on a dark road to confirm the beams light the road properly and don't blind oncoming drivers.

Know when to stop and seek professional help

If the adjustment screws won't turn, are stripped, or if you cannot locate them after checking your owner's manual, stop. Forcing a stuck screw or guessing at the location can damage the headlight housing or adjustment mechanism, leading to a costly repair. A shop can handle these cases and may have specialized tools to access screws you cannot reach.

Similarly, if your headlights are sealed units with no external adjustment screws, or if the beam position doesn't change despite multiple adjustments, the headlight assembly itself is likely faulty and needs replacement. This is not a repair you can complete with a screwdriver, and attempting to disassemble a sealed headlight usually destroys it.

Frequently Asked Questions

How often should I adjust my headlights?

Headlight aim can shift if you hit a pothole, have a collision, or if the vehicle's suspension settles over time. Check your aim once a year or whenever you notice the beam pattern looks wrong. Most vehicles don't need adjustment more than once every few years under normal driving.

Do I need to remove the headlight to adjust it?

No. The adjustment screws are on the back of the housing and are accessible from inside the engine bay. Removing the headlight is unnecessary and adds time and complexity. Only remove it if you cannot reach the screws otherwise, or if the headlight itself needs replacement.

What if one headlight is much brighter than the other?

Uneven brightness usually means one bulb is failing or oxidized, not an aim problem. Both beams should be equally bright. If one is noticeably dimmer, replace that bulb first, then check the aim. If both are equally bright but the aim is still off, proceed with the adjustment screws.

Can I adjust my headlights at night without a wall?

You need a flat vertical surface to see the beam pattern clearly. A wall, garage door, or even a large piece of plywood works. Adjusting by eye on the road is unreliable because you cannot see the exact beam position. Do the wall test in daylight or with the garage door closed and lights off inside.

What if my vehicle has LED or HID headlights?

The adjustment process is identical — LED and HID headlights use the same mechanical adjustment screws as halogen bulbs. The only difference is the brightness and color of the beam, not how you aim it. Adjust them the same way and check the wall to verify the position.