Adjusting Headlight Aim

*MEDIUM*

You should not need to periodically adjust the aim of your headlights. Once set, the headlights should remain aimed correctly. If the headlight aim cannot be retained, then the adjusting screws are faulty and should be replaced.

Headlight aim can usually be adjusted with two screws near the headlight socket. The screw on the side of the socket would control horizontal (left and right) aim. The screw on the top of the socket would alter vertical (up and down) aim. The adjusting screws typically have a Phillips head. You can adjust headlight aim according to the following procedure:

1. First, inspect the condition of your car. Make sure all four tires are properly inflated and the fuel tank is half full. Remove any temporary cargo of significant weight from the trunk. Bounce the car several times at each corner to settle the suspension.
2. Next, position your car on level ground with the front end perpendicular to and 25 feet from a wall. Select a wall on which markings can be made or place a board against the wall instead. Park the vehicle with the engine OFF, the parking brake engaged, and the transmission in PARK (for automatic) or REVERSE (for manual).
3. Draw lines on the board or wall that represent the vertical centerlines of the car and each headlight. If the car has two headlights, three lines will be drawn; if it has four headlights, five lines will be drawn. Finally, draw a horizontal line that represents the height of the headlight centers from the ground. Use a yardstick or tape measure.
4. Wait for dusk if necessary for sufficient contrast to identify the headlight beam hot spot (location of brightness intensity). Turn on the high beam headlights and cover the headlight on one side of the car.
5. Adjust the aiming screws of the headlight so the high beam hot spot is focused on the intersection of the horizontal centerline and that headlight's vertical centerline. Repeat for the opposite high beam headlight.
6. Switch the headlights to low beam and cover one side again. Adjust the aim of the low beam hot spot so its top is at the horizontal centerline. Adjust the aim further so the hotspots left edge is 2" to the right of the headlamps vertical centerline. Repeat for the opposite low beam headlight. See Headlight Aiming Diagram.
7. If your vehicle has a combination high and low beam headlight, the low beam aim should automatically be correct if the high beam is properly aimed.

SYSTEMS
LIGHTS & SWITCHES
TESTING HEADLIGHT AIM
VARIATIONS