Adjusting the aim of the headlights on a Mercedes-Benz ML320 is necessary whenever a headlight bulb is replaced. If visibility is poor in low light driving conditions, the headlights may need to be adjusted. Checking the aim of the headlights should also be part of regular maintenance. By adjusting the low beam, the fog lamp and high beam will automatically be adjusted.
Park the ML320 on a level surface, 25 feet from a vertical wall. Park the vehicle so that it is perpendicular to the wall, with the headlights facing the wall.
Measure the distance from the ground to the outer reference point found on each headlight lens. The reference point is a small circle, located close to the center of the headlight.
Mark the wall at the same height that was measured from the ground to the headlight reference point. Place a horizontal strip of tape along the wall at the height that is marked.
Open the hood of the car. Remove the access covers from the top of each headlight assembly. Turn the headlights on.
Locate the adjusting screw on the top of the headlight assembly. Turn the adjusting screw counter-clockwise to move the headlight beam down. Turn the adjusting screw clockwise to move the headlight beam up. Adjust the headlight beams so that the top of the beam is level with the tape line on the wall.
Replace the headlight assembly access covers.
