How are Headlamp Alignment Adjusts diagnosed?
Before checking if the headlamps are misaligned, a technician will first rule out any other causes of some of the symptoms. For instance, if poor visibility at night is the concern, deteriorated or foggy headlamp lenses could be the problem. So could low voltage from a bad wire or a weak alternator. If it appears that the headlamps are out of alignment, a technician will park the vehicle on level ground, facing a wall at a measured distance, and determine whether the headlamps illuminate the wall at specific locations. Lights that shine away from the correct spots will need to be adjusted.
How are Headlamp Alignment Adjustments done?
To align headlamps in modern vehicles, a technician will often use the same method used during diagnosis: park the vehicle on level ground facing a wall that is marked at the proper locations for the headlights to shine. If a light shines outside of its parameters, the technician will turn a set of adjusting screws located on the headlamp assembly to bring it into alignment up and down, left and right. Many vehicles incorporate leveling meters on the headlamp assembly to aid in proper aiming. Older vehicles that did not incorporate levels, instead included mounting tabs on the outside of the headlights that articulated with a special alignment tool. A technician would use this special tool to make sure the lamp was level.
RepairPal Recommendations for Headlamp Misalignment issues
Proper headlamp operation and alignment is essential for vehicle safety. Have a qualified technician determine if the headlamps are out of alignment, or if there is some other cause for poor visibility.
What to look out for when dealing with Headlamp Alignment Adjust issues
The headlamp adjusting screws used to aim the lamps can corrode with time and lack of use. It is not uncommon for headlamp adjusting screws to freeze up or break during adjustment and need replacement. (In come cases the headlamp assembly might need to be replaced). It is also possible that a headlamp is not capable of being adjusted because surrounding components were damaged in a front end crash. Even a minor collision can bend or break headlamp mounting locations and prevent the light from being adjusted properly.