Lincoln 2000 Continental Owner's Manual page 202

Maintenance and care
A bubble (vertical indicator) that is not centered between the two red
lines does not necessarily indicate out-of-aim headlamps. If your vehicle
is not positioned on a level surface, the slope will be included in the
vertical indication. Therefore, vertical and horizontal headlamp
adjustment should be performed only when the beam direction appears
to be incorrect.
You will need one 4 mm wrench or socket to make the adjustments.
If the vehicle has been in an accident, the vehicle's front structure
should be properly aligned before aiming the headlamps.
Horizontal aim adjustment
1. Park the vehicle on a level
surface.
2. With the hood open, remove the
protective cover, locate the
horizontal indicator and the
adjusting screw at the rear of the
D
headlamp assembly.
U
3. Use a 4 mm wrench or socket to
turn the horizontal adjusting screw
until the "0" mark on the yellow dial
lines up with the reference mark on
the marker (as shown) when viewed
directly from above.
202