How to Adjust Your Car's Headlights

Have you ever experienced a situation where your headlights don’t shine directly onto the road in front of you or cause discomfort to oncoming drivers? If the headlights are shining onto the tree branches or an oncoming driver keeps flashing their high beams or honking their horn, it’s likely that the headlights are misaligned and blinding other road users. Fortunately, adjusting the headlights is a simple task that only requires a few measurements and a screwdriver.

Balance the car. Start by removing any heavy items from the car’s trunk to achieve balance. Also, check if the tire pressures are within the manufacturer’s recommended levels. If possible, have someone sit in the driver’s seat while filling the gas tank to about half. Additionally, ensure that the headlight aiming adjustment gear (if available) is set to zero.

Find a parking spot. Park your car on level ground, about 3 to 4.6 meters away from a wall or garage door with the car facing towards the wall. A cemented parking space or a flat garage entrance is ideal for this task.

• Bounce the car down on all four corners to allow the suspension to settle.
• Measure the distance from the ground to each headlight to ensure the suspension is balanced.

Turn on the headlights. Do not use low beams or fog lights. Use tape to mark two 'T' shapes on the wall or garage door, with vertical and horizontal lines crossing through the center of the headlights.

Verify that the headlights are properly aligned. Place a carpenter's level between the two marks you made to check if they are even. If they aren’t, use a tape measure to check the distance from the lower mark to the ground and adjust the other side to match. These marks should not be higher than 1.1 meters from the ground.

Move the car back exactly 7.6 meters from the wall or garage door. Don't estimate; measure the distance with a tape measure to ensure accuracy. Once done, turn off the headlights. Remove the trim around the headlights and adjust the screws. The adjustment screws are typically located near the headlights, but some manufacturers place them behind the headlights in the engine compartment. The screws are labeled for horizontal and vertical adjustments.

• Always follow the specifications in the user manual. Different manufacturers recommend different distances for headlight adjustments. For example, Toyota recommends 3 meters, Pontiac GTO recommends 4.6 meters, and Chrysler suggests 0.9 meters for certain models. Make sure to refer to the manual for specific instructions.
• The screw above the headlights adjusts the vertical alignment, while the screw on the side adjusts the horizontal alignment. Some cars may use bolts instead of screws.

Adjust each headlight individually. Cover one headlight with a cloth or towel and check the beam from the other headlight. This ensures that the light beams do not overlap, making the adjustment process easier. Have someone sit in the driver's seat to turn the headlights on and off while you make the adjustments.

Turn the screw or bolt above to adjust the vertical alignment. Turning it clockwise will raise the beam, while turning it counterclockwise will lower it.

• After making the adjustments, turn the headlights on again and check the light pattern on the wall. The top edge of the brightest light should align with or be just below the center of the 'T' mark you made.

Turn the screw or bolt on the side to adjust the horizontal direction. Now, proceed in the same manner with the screw or bolt located on the side to adjust the headlight direction horizontally. The majority of the bright center beam of the headlight should be positioned to the right of the vertical tape line (or to the left if traffic laws in your country require driving on the left side of the road).

Test the direction of the headlights on the road. Take the car for a short drive to check if the headlights are properly adjusted. If necessary, repeat the adjustment steps above.

• After adjusting the headlights, shake the car vigorously and recheck the light pattern on the wall or garage door. Some user manuals suggest doing this step after making the adjustments. Follow the instructions, then check and readjust if necessary.
• Look for a small carpenter's level mounted above the headlight. Some car manufacturers include this feature to aid in headlight adjustment. Acura and Honda are two brands that have integrated small levels into their cars. This design is especially handy when a carpenter's level is not available.
• In Vietnam, using high beams in urban areas and densely populated neighborhoods is against the law.
• It’s recommended to check the headlights once a year to ensure they are properly aligned.

• Our eyes will temporarily fail to see anything when exposed to high-intensity light directly. This means misaligned headlights can affect both you and others on the road.
• If your headlights are misaligned and you cannot adjust them yourself, make sure to visit a service station promptly for a technician to inspect and resolve the issue.

• Wrench or Phillips screwdriver
• Adhesive tape
• Measuring tape
• Carpenter's level (if needed)