How To Adjust Headlights

Prepare your vehicle

• Check the air pressure of your tires, topping them off if necessary.
• Ensure the gas tank is at least half full so the vehicle weighs about the same as it would when driving.
• As night falls, park your vehicle in a flat area about 25 feet in front of a smooth vertical surface, like the wall of a building.
• If you can’t find a suitable building, set up a sheet of plywood 25 feet in front of your vehicle. Lean the plywood against a sawhorse, or fasten it with an impact driver and deck screws.

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• Grab a solid part of your vehicle, like the floor with the door open, the metal framework beneath the hood or the trailer hitch. Push down on your vehicle several times so it bounces up and down on the suspension, then comes to rest. This ensures the vehicle sits as flat as possible.

Mark the center point of headlights

• Use a tape measure to determine the distance from the ground to the center point of one of your headlights; i.e. the area of the lens directly over the low-beam bulb.
• Mark this spot on the headlight by making a small dot with a dry-erase marker.
• Make a corresponding mark on the other headlight.
• Measure and record the horizontal distance between these two marks.

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Prepare your reference surface

• Make a series of pencil marks on the wall of the building or the plywood at the same height as the mark on your headlight.
• Apply an eight-foot piece of painter’s tape to the wall or plywood along the marks you’ve just made.

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• Measure down four inches from the top of the tape in the left one-third of your plywood sheet. Then apply a two-foot-long strip of tape at this height, parallel with the long strip above.
• Repeat the procedure on the right one-third of the plywood, but apply this short strip of tape only two inches from the top strip. You may need to adjust them later. Make nighttime driving safer with HID headlights.

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Determine headlight aiming requirements in your area

• Follow any recommendations for headlight aiming found in your owner’s manual.
• Research any headlight height requirements in your area. Some U.S. states enforce headlight-specific height requirements. Apply these parameters before proceeding to the next step.

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Adjust your headlights

• Pop your hood and find your vehicle’s headlight adjustment bolts or gears. They should be behind the headlights. Check your owner’s manual if you have trouble finding them. Most vehicles have only one adjustment bolt, screw or gear per headlight assembly, which adjusts the vertical position of low-beam and high-beam bulbs together. Some feature a separate bolt or gear nearby for horizontal adjustment.
• Turn on your vehicle and flip on your low beams. Note where the beams land on the wall or plywood.
• Use a socket wrench or screwdriver to slowly adjust the vertical direction of your driver’s side headlight. Before you move ahead, get to know the difference between LED and halogen headlights.

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• Aim the driver’s side headlight so the top edge of the beam is level with the short piece of tape, four inches below the top edge of your long piece of tape.
• Adjust the passenger side headlight in the same way, aligning the top of the beam with the other short piece of tape two inches below your long piece. For most vehicles, adjusting your low beams will automatically adjust high beams as well.