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DIY Headlamp Adjustment Guide

Maladjusted headlights can impair your vision and other drivers' visibility.

Maladjusted headlights can impair your vision and other drivers' visibility.

Headlamp adjustment helps you correct visibility issues on the road that can cause serious problems not only for you but for oncoming traffic as well. Maladjusted headlamps impair your visibility when driving at night and can impair visibility for oncoming drivers.

Unfortunately, few car models offer a headlight aiming feature that lets the driver adjust the headlamps from inside the car. Still, aligning headlights usually requires just a Phillips screwdriver, an area with enough space and an aiming surface. So you can adjust your headlights without special equipment. Whether your lamp assembly comes equipped with a built-in level or not, the following procedure will help you check and correct your car headlights.

Index

* Headlight Adjustment Checklist

* How to Adjust Headlights Fitted with Aligning Screws

* What If My Adjusting Mechanism Doesn't Work?

* How to Adjust Headlights Fitted with a Leveling Bubble

* 6 Tips to Keep Your Headlights in Working Order

* VIDEO: How to aim your headlights

Poll - How often do you adjust your headlights?

Headlight Adjustment Checklist

To set your car to the average height for most driving conditions, car manufacturers recommend the next steps before and while adjusting your headlights:

Have the fuel tank half full.

Empty the trunk—except for car jack and stands.

Check and inflate your tires to the recommended pressure (consult your car owner's manual).

Have one person seating behind the wheel while adjusting the headlights.

Optionally, have another person seating at the passenger side as well (recommended).

How to Adjust Headlights Fitted with Aligning Screws

Older vehicle models come with sealed-beam lamps. These type of lamps use a set of adjusting screws to readjust aiming as needed. Although not as easy to adjust as modern headlights, you still can reset the lights at home using a Phillips screwdriver, masking tape and an aiming surface.

1. Choose a level surface near a wall or flat surface you can use to project and adjust the lights on.

2. Drive your vehicle a few inches from the wall or aiming surface.

3. Using masking tape, make a cross on the wall that corresponds to the center of each lamp. Use about 8 inches of tape for the vertical and the horizontal line of the cross.

4. Repeat the previous step for the other pair of headlights, if your vehicle uses a 4-headlight system.

5. Backup your car slowly in a straight line to set your headlights 25 feet from the aiming surface.

6. Go under the hood and find the two adjusting headlamp screws (or bolts on some models).

On older models, you may need to remove the trim ring from the headlights to access the adjusting screws at the front of the assembly. You'll find one of these spring-loaded screws on the top or bottom of the headlamp. This screw adjusts the lamp vertically (up and down movement). Turning the screw clockwise or counterclockwise will rise or lower the height of the light.

7. Find the horizontal adjustment screw (left and right movement) to the left of right of the headlight assembly. Some models may not have this adjustment. So it's a matter of adjusting how the assembly seats at the support.

8. Turn on the low beams and check that most of the brightest area of the light projects below the horizontal line of the cross and mostly to the right (away from oncoming traffic) of the vertical line of the cross.

9. Use a Phillips screwdriver to adjust each headlamp, as necessary.

10. After adjusting the low beams, turn on the high beams (if they have their own headlight).

11. The brightest spot from the high beams should project on the vertical line, just below the horizontal line or close to it.

How to Adjust Modern Headlights

Newer vehicle models use headlights with halogen headlamp bulb inserts and, some models, a leveling bubble to adjust headlight aiming. Basically, you simple turn the adjusting screws until the headlight is aiming according to the marks on a vertical surface, or the bubble centers in the leveling mechanism. Although headlights with a leveling mechanism are easier to adjust than previous models, you may still want to use an appropriate aiming surface to verify correct aiming of the lights.

1. Just like in the previous method, select a level surface close to a wall or flat surface to project and adjust the lights on.

2. First, move your vehicle close to the wall or aiming surface.

3. On the wall, mark the center of each headlight with a vertical and horizontal line (about 8 inches in length) using masking tape.

4. Now, backup the car slowly in a straight line so the headlights are about 25 feet from the aiming surface.

5. Turn off the engine and open the hood.

6. You'll see a built-in level next to each headlight.

7. Use a Phillips screwdriver to turn the headlight housing screws to move the bubble to the center of the leveling indicator.

8. When you turn on the low beams, the center of the brightest spot of the light should project about two inches below the horizontal line of the cross and about two inches to the right of the vertical line of the cross.

9. Continue adjusting the lights as necessary.

10. After adjusting the low beams, check that the brightest spot from the high beams project on the vertical line of the cross, just below the horizontal line or fairly close to it.

6 Tips to Keep Your Headlights in Working Order

1. Are the Headlamp lenses blurred?

Modern headlamps come in a sealed plastic shell with a plastic lens that tends to cloud over due to dust and oxidation build-up, blurring and dimming the beam of light. This makes it hard to see the road ahead at night. You can restore the lens clarity by polishing the lens with a special cleaning kit.

2. Are the headlamps free of water?

A similar effect can have condensed water inside the lens. This happens on headlamps with plastic shells. Water finds its way into the housing and condenses as the lens temperature rises, blurring the projected beam. One way to prevent condensation is to drill a small hole at the bottom of the plastic housing to allow water to leak through.

3. Are the high and low beams working on both headlamps?

If you tend to do most of your driving during the day and haven't changed your headlight bulbs in a long time, verify that both the low and high beams work correctly before driving at night, specially if you are going to travel. It sucks to find out one of your high beams doesn't work once you are a few miles away from the nearest town to buy and replace a head lamp.

4. Are the electrical connectors rust free and tight?

Corrosion and loose electrical connectors may cause the headlights to fail or flicker. A visual inspection can reveal the accumulation of rust. Use white silicone lubricant for electrical contacts to prevent corrosion. Make sure the socket is locked in place and the connections are tight.

5. Are the headlamps assemblies and support in good shape?

Check for cracks and missing pieces around the support, hold-down mechanism and the assembly (including the reflector inside the light housing). Otherwise, your headlamp will be impossible to aim at the correct angle.

6. Is the adjusting mechanism working properly?

Check that the adjusting screws or mechanism is free of corrosion, dust and debris. A few drops of penetrating oil from time to time will help protect it from rust.

The next video will give you visual reference to adjust your headlights at home.

Check headlamp adjustment at least once a year, as suggested by car manufacturers. Also, adjust them any time you replace the headlamp housing, or after performing some front end body work. This will help improve your visibility at night, and avoid glaring at oncoming drivers and causing an accident. So keep this helpful guide handy and check your headlights again next year.