2009 Hummer H3T Alpha Owner's Manual - Page 276

5-40 Service and Appearance Care This should allow only the beam of light from the headlamp being aimed to be seen on the wall. To adjust the vertical aim: 1. Open the hood. See Hood Release on page 5-9. 3. At a wall, measure from the ground upward the recorded distance from Step 2 and mark it. 2. Record the distance from the ground to the aim dot on the headlamp. 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. 5. Turn on the headlamps and place a piece of cardboard or equivalent in front of the headlamp not being aimed. 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.