2010 Hummer H3 Owner's Manual - Page 300
2010 Hummer H3 Manual
Page 300 highlights
10-34 Vehicle Care 5. Turn on the headlamps and place a piece of cardboard or equivalent in front of the headlamp not being aimed. This should allow only the beam of light from the headlamp being aimed to be seen on the wall. 3. At a wall, measure from the ground upward the recorded distance from Step 2 and mark it. 4. Draw or tape a horizontal line the width of the vehicle at the wall where it was marked it Step 4. Notice: Do not cover a headlamp to improve beam cut-off when aiming. Covering a headlamp may cause excessive heat build-up which may cause damage to the headlamp. 7. Turn the vertical aiming screw until the headlamp beam is aimed to the horizontal tape line. Turn it clockwise or counterclockwise to raise or lower the beam. Passenger Side Shown 6. Locate the vertical headlamp aiming screws, which are under the hood near each headlamp assembly. The adjustment screw can be turned with an E8 Torx® socket or T15 Torx® screwdriver. The top edge of the cut-off should be positioned at the bottom edge of the horizontal tape line. 8. Repeat Steps 7 and 8 for the opposite headlamp.