ESM Headlamps - Aiming Procedures
Group Ref.: 10 - BodyBulletin No.: 431505
Date: August, 1994
SERVICE MANUAL UPDATE
SUBJECT:
ESM HEADLAMPS - HEADLAMP AIM (NEW PROCEDURE)
MODELS:
1991-94 BUICK PARK AVENUE
1992-94 BUICK LE SABRE
This bulletin represents new information for the Headlamp Section of the appropriate Buick Electrical Systems Manual. Please add the following procedure to the Headlamp Section.
HEADLAMP AIMING
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 important because of their increased range and power, 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. Composite headlamps, however, do not require aiming after the bulb has been replaced.
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. When using mechanical aimers, follow the manufacturer's instructions.
To prepare the vehicle for aiming the headlamps, perform the following:
1. Completely assemble all components.
2. Place vehicle on level pad or surface.
3. Stop all unnecessary operations or work on vehicle that affects vehicle trim.
4. Close doors.
5. Stabilize suspension.
6. Be sure fuel level is 1/2 tank or less.
7. Be sure tires are inflated to proper pressure.
Screen Headlamp Aim Adjustment (Preferred) Refer to Figure 1 for proper headlamp aim adjustment measurements.
Mechanical Headlamp Aim Adjustment (Optional)
Tool required: J 25300-E, headlamp aiming kit, (or equivalent)
The headlamp aiming equipment should be designed to accommodate all composite headlamps in any standard shape or size and in any configuration. Different light shapes and sizes are accommodated through the use of adapters as provided in the J 25300-E headlamp aiming kit. Regardless of configuration, headlamps are always aimed in pairs.
The mounting and adjustment instructions are Included in the J 25300-E headlight aiming kit.
1. The universal aimer should be used on a known level floor or calibrated for floor slope.
2. Select and assemble the universal adapter that fits the aiming pad pattern on the lens of the headlamp.
3. Move the adjustment rods to the number that agrees with the number located on the headlamp lens.
4. Attach adapters making certain that the correct adapter is used with the correct side aimer.
5. Place the aimers with adapters on to their respective sides making sure all adjustment rods are contacting the aiming pads. It may be necessary to add or remove an extension stud.
6. Aim headlamps according to the instructions included in J 25300-E, headlamp aiming kit.