2008 gmc sierra headlight adjustment for up and

You don't need to measure up. Pull up to a wall, put the bumper against the wall and use a small level to aim the headlights level at the wall, then mark the wall with chalk where the main beam is. Then back up 25 feet and the main beam of the headlight needs to be at that level or a few inches below. Adjust to achieve that and you are done.

The service and repair manual with a diagram which will help you to locate and fix the problem on your own and you will get the manual from the given link http://toolsnyou.com

Here are directions....

1. Park the vehicle on a level surface, with the fuel tank about 1 / 2 full and with the vehicle empty of all extra cargo (unless normally carried). The vehicle should be facing a wall which is no less than 6 feet (1.8m) high and 12 feet (3.7m) wide. The front of the vehicle should be about 25 feet from the wall.

Fig. Fig. 5: Location of the aiming screws on most vehicles with sealed beam headlights

Fig. Fig. 6: Dual headlight adjustment screw locations-one side shown here (other side should be mirror image)

Fig. Fig. 7: Example of headlight adjustment screw location for composite headlamps

1. If aiming is to be performed outdoors, it is advisable to wait until dusk in order to properly see the headlight beams on the wall. If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over the windows.
2. Turn the headlights ON and mark the wall at the center of each light's low beam, then switch on the brights and mark the center of each light's high beam. A short length of masking tape which is visible from the front of the vehicle may be used. Although marking all four positions is advisable, marking one position from each light should be sufficient.

Fig. Fig. 8: Low-beam headlight pattern alignment

Fig. Fig. 9: High-beam headlight pattern alignment

1. If neither beam on one side is working, and if another like-sized vehicle is available, park the second one in the exact spot where the vehicle was and mark the beams using the same-side light. Then switch the vehicles so the one to be aimed is back in the original spot. It must be parked no closer to or farther away from the wall than the second vehicle.
2. Perform any necessary repairs, but make sure the vehicle is not moved, or is returned to the exact spot from which the lights were marked. Turn the headlights ON and adjust the beams to match the marks on the wall.
3. Have the headlight adjustment checked as soon as possible by a reputable repair shop.

there is an adjustment screw on the headlight bucket

You have to remove the air intake filter and then kind of reach around up in there to change it. It can be done, but is a lot of work. Then you can just sort of reach in and change both headlights. A very big pain to change a couple of headlights. Make sure not to touch the glass on the light because the oil on your skin can cause it to fail sooner. HeadLight (Low Beam) H11 HeadLight (High Beam) 9005 Thanks -david

check your headlamp switch.is your switch on the dash or part of the turn signal switch.gm have a thing with plastic switches and metal contacts these switchs have a tendency to melt..also check for grounds.was the vehicle in a accident involving the front end.if you changed your headlamps to 80/100 watts bulbs.the circuit breaker may not work hence the switch melts.

Note: The headlights must be aimedcorrectly. Ifadjusted incorrectly they could blind the driver of an oncoming vehicle andcause a serious accident or seriously reduce your ability to see the road. Theheadlights should be checked for proper aim every 12 months and any time a newheadlight is installed or front end body work is performed. It should beemphad that the following procedure is only an interim step which willprovide temporary adjustment until the headlights can be adjusted by a properlyequipped shop. 1-Identify the exact location of the adjustment screws: a) On halogen bulb style headlights, theadjustment screws are located on top of the housing. b) On sealed beam style headlights, theinboard (vertical) adjustment screw and the upper (horizontal) adjustment screware accessible on the exterior of the vehicle. 2-There are several methods of adjusting the headlights. Thesimplest method requires masking tape, a blank wall and a level floor. 3-Position masking tape vertically on the wall inreference to the vehicle centerline and the centerlines of both headlights. 4-Position a horizontal tape line in reference to thecenterline of all the headlights. Note: It may be 'easier to position thetape on the wall with the vehicle parked only a few inches away. 5-Adjustment should be ,made with the vehicle parked 25 feetfrom the wall, sitting level, the gas tank half-full and no heavy load in the vehicle. 6-Starting with the low beam adjustment, position thehigh 1ntensity zone so it is two inches below the horizontal line and twoinches to the side of the headlight vertical line, away from oncoming traffic. Adjustmentis made by turning the top (sealed beam) or inner (aerodynamic type) adjustingscrew clockwise to raise the beam and counterclockwise to lower the beam. The adjusting screw on the side should beused in the same manner to move the beam left or right. 7-With the high beams on, the high intensity zone shouldbe vertically centered with the exact center just below the horizontal line. Note: It may not be possible to positionthe headlight aim exactly for both high and low beams. If a compromise must be made,keep in mind that the low beams are the most used and have the greatest effecton safety. Have the headlights adjusted by a dealerservice department or service station at the earliest opportunity -

every headlamp has two adjusting set screws. One for vertical and horizontal. They are normally a torx driver socket that will turn these screws. If you have a garage use the garage door at night to set the beams reflecting off the door. Centering the truck to a center mark on the door would be helpful when you make the adjustments. That way your headlamps should aim evenly. Please note if your driveway is not level jack up the trucks rear end to make it so. Leveling the vehicle makes the difference before any adjustments are mad

The adjustment screws/nuts should be located either on the top of the headlamp assembly, behind the headlamp assembly, or near the frame rail by the radiator support.

You will have vertical adjustment screws for each independent beam (separate highs and separate lows, but will be same screw if highs and lows are the same bulb). You may also have additional horizontal adjustment screws as well

Park your car on a level ground 30 feet from a wall and measure the height from the ground to the bulb and mark on a wall (do this for highs beams and low beams if the bulbs are separate, if highs and lows are the same bulb, only do it for the lows)

For Low Beams: If the headlights read VOR, then aim the brightest part or cutoff part just below the mark on the wall. If it says VOL or nothing, aim them 2 inches below the mark on the wall.

For High Beams (if separate from low beams): Aim the headlight directly at the line you marked on the wall.

Yes you can. There is an adjustment screw at the top of each head lamp and you just turn them out or counter clockwise and the beam will come down. You may also have to adjust them side to side also. There is an adjustment screw as well.