Headlamp: Adjustments

The headlamps must be properly aimed in order to obtain the maximum road illumination and safety that has been built into the headlamp system. With composite headlamps, proper aiming is even more important because the increased range and power of these headlamps make even slight variations from recommended aiming hazardous to approaching motorists. Composite headlamps, however, do not require aiming after the bulb has been replaced.


When checking headlamp aim, the vehicle must be at normal weight (with fuel, oil, water and spare tire). Tires must be uniformly inflated to specified pressure. If the vehicle will regularly carry an unusual load in the rear compartment, or a trailer, these loads should be on the vehicle when the headlamps are checked. All states have requirements for headlamp aiming and they must be followed.

Headlamp aim should be checked when a new headlamp assembly is installed; or if service or repairs to the front end area have (or may have) disturbed the headlamps or their mountings.

Headlamp focus is set when the unit is made; no adjustment for focus is necessary or possible.

Some state and local laws specify requirements for headlamp aim; these laws must be followed.

Horizontal aim is done by an adjusting screw on the outer side of the headlamp assembly. Vertical aim is done by an adjusting screw in the top center of the assembly.

To prepare the vehicle for aiming the headlamps perform the following:
^ Completely assemble all components.
^ Place vehicle on level pad or surface.
^ Stop all unnecessary operations or work on vehicle that affects vehicle trim.
^ Lose doors.
^ Stabilize suspension.
^ Be sure fuel level is 1/2 tank or less.
^ Be sure tires are inflated to proper pressure.