Headlamp: Adjustments

GENERAL INFORMATION
The headlamps are equipped with a bubble level for up/down headlamp alignment. The bubble is centered with the vehicle on a level surface. A horizontal gauge and magnifying window is located next to the bubble level for left/right alignment. Aim on every headlamp assembly is calibrated at the headlamp manufacturer. At the vehicle assembly plant, the vertical aim is set by centering the bubble with the vehicle on a level surface. Horizontal aim is controlled by the mounting pads on each headlamp mounting panel. When the vehicle is to be used with a heavy load, the bubble level
can be used to compensate for the altered ride height.









HEADLAMP/FOG LAMP ADJUSTMENT USING ALIGNMENT SCREEN

1. Position vehicle on a level surface perpendicular to a flat wall 7.62 meters (25 ft.) away from front of headlamp lens.
2. If necessary, tape a line on the floor 7.62 meters (25 ft) away from and parallel to the wall.
3. From the floor up 1.27 meters (5 ft), tape a line on the wall at the centerline of the vehicle. Sight along the centerline of the vehicle (from rear of vehicle forward) to verify accuracy of the line placement.
4. Rock vehicle side-to-side three times to allow suspension to stabilize.
5. Jounce front suspension three times by pushing downward on front bumper and releasing.
6. Measure the distance from the center of headlamp lens to the floor. Transfer measurement to the alignment screen (with tape). Use this line for up/down adjustment reference.
7. Measure distance from the centerline of the vehicle to the center of each headlamp being aligned. Transfer measurements to screen (with tape) to each side of vehicle centerline. Use these lines for left right adjustment reference.


HEADLAMP ADJUSTMENT
A Properly aimed low beam headlamp will project the center of the low beam hot spot on the alignment screen 229mm (9 in.) 50mm (2 in.) below the headlamp centerline. The center of the hot spot should be 100mm (4 in.) 50mm (2 in.) right of the headlamp centerline. The high beams on a vehicle with aero headlamps cannot be aligned. The high beam pattern should be correct when the low beams are aligned properly. To adjust headlamp alignment, rotate alignment screws to achieve the specified low beam hot spot pattern.



BUBBLE LEVEL CALIBRATION
After the headlamp alignment has been verified or set and the bubble level is not centered, calibrate the bubble level.


1. Remove screws holding magnifying window to top of headlamp module.
2. Position magnifying window to the side between headlamp module and radiator panel.
3. Through slotted hole in magnifying window insert small screw driver into bubble level calibration screw.
4. Rotate screw in proper direction until bubble is centered on the "O."
5. Install magnifying window.
6 If necessary, calibrate magnifying window.




MAGNIFYING WINDOW CALIBRATION
After the headlamp alignment has been verified set and the magnifying window is not centered, calibrate the magnifying window.

1. Loosen screws holding magnifying wind top of headlamp module.
2. Using the calibration knob above head lens, rotate magnifying window until window is centered over the "0" on the gauge below the window.
3. Tighten screws to hold magnifying window to headlamp module.









FOG LAMP ALIGNMENT
Prepare a alignment screen. A properly aligned fog lamp will project a pattern on the
alignment screen 100mm (4 in.) below the fog lamp centerline and straight ahead. To improve visual interpretation of the fog lamp pattern on the alignment screen, disable the headlamps by removing the headlamp fuses from the power distribution center.