Headlamp Aiming Information

All equipment for testing headlamps must comply with the Society of Automotive Engineers Recommended Practice for Headlamps Inspection Equipment.

Mechanical Aimer - if mechanical aimer is used, it shall be in good repair and adjustment, and shall be used according to the manufacturer's instructions and must be calibrated to the slope of the floor on which the vehicle stands.

Headlamp Testing Machine - If a headlamp testing machine is used, it shall give results equivalent to those obtained using the screen procedure shown below. It shall be in good repair and adjustment, and shall be used in accordance with the manufacturer's instructions. The machine using a photoelectric cell or cells to determine aim should also have a visual screen upon which the beam pattern is projected proportional to its appearance and aim on a screen at 25 feet. Such visual screen shall be plainly visible to the operator and should have horizontal and vertical reference lines to permit visual appraisal of the lamp beam.

Headlamp Aiming by the Screen Method - First locate the vehicle so that it is square with the screen and with the front of the headlamps directly over a referetice line which has been painted on the floor. Next locate the center line on the aiming screen so that it is in line with the center of the vehicle. This can be done as shown below by sighting


through the center of the rear window of the vehicle and over the hood ornament - have vehicle moved until it is in alignment with these two points. If there is not center hood ornament, mark the center of the front and rear windows with narrow strips of masking tape. Use these "sights" to locate the center line of the aiming screen directly in line with the vehicle axis.

Aiming Area Required - It is desirable to have a specific aiming area in a darkened location. This should be sufficient for the vehicle and an additional 25 feet measured from face of lamps to the front of the visual screen. The floor on which the car rests must be flat, and level with the bottom of the screen. If the floor is not level, compensate.

Aiming Screen - If a screen is used, it should be 5' high x 12' wide with a matte white surface well shaded from extraneous light, and properly adjusted to the floor on which the vehicle stands. Provisions may be made for moving the screen so that it can be aligned parallel with the rear axle and so that a horizontal line drawn perpendicularly form the centerline of the screen will pass an equal distance midway between the two headlamps. The screen shall be proveded with a fixed vertical centerline, two laterally adjustable vertical tapes, and one vertically adjustable horizontal tape. If a regular commercial aiming screen is not available, the screen may consist of a vertical wall having a clear uninterrupted area approximately 6 feet high and 12 feet wide. The surface should be finished with a washable non-gloss white paint. After the aiming screen has been set up in its permanent location. It is necessary to paint a reference line on the floor directly under the lens of the lamps to indicate the proper location of the headlamps when they are being aimed.