1997 Cadillac DeVille Owner's Manual - Page 318

2. Check the vertical headlamp aim first. Keep in mind that your vehicle needsto be on a level surface. Turn the vertical aiming screw until bubble inside the the level is centered at "0." 3. After the vertical aim is correct, check the horizontal aim for each headlamp and adjust as necessary. Turn the horizontal aiming screw until the end the of screw aligns with the "0." 4. Recheck the vertical aimto make sure it remains correct after the horizontal aim adjustment. Adjust as necessary.