How to Adjust Low Beam Headlights That Illuminate Too Close?
4 Answers
The key points for adjusting low beam headlights are as follows: 1. Adjust facing a wall: Position the car perpendicular to a wall, approximately 10 meters away. 2. Use high beams for adjustment: Generally, if the high beams are properly adjusted, the low beams will also be correct. It's advisable not to adjust using low beams alone as it's harder to determine if the high beams are properly aligned. 3. Adjust one at a time: Cover the light not being adjusted with a cloth and adjust them one by one. Below are precautions for adjusting low beam headlights: 1. Adjusting height: If the headlights haven't been replaced, usually only height adjustment is needed, as the left-right alignment is typically accurate. 2. Adjusting headlights: Note that the left headlight (from the driver's perspective) should be slightly lower than the right one to avoid dazzling oncoming vehicles, which could compromise safety. 3. Nighttime adjustment: It's best to adjust at night, but avoid doing so on roads due to safety concerns and poor visibility of the adjustment effects. Opt for a residential area or a courtyard instead. Prepare a flashlight as it's hard to see clearly at night.
As a DIY enthusiast who has adjusted my car's headlights several times, I can share that adjusting the low beams is actually quite simple. First, park your car on level ground about 3 meters from a wall. Open the hood and locate the adjustment holes behind the headlights. Typically, the screw near the wheel arch controls vertical adjustment, while the one near the grille adjusts horizontal alignment - just turn them slowly with a Phillips screwdriver. Watch the cutoff line on the wall as you adjust: the standard is to have the driver's side beam 1-2cm lower than the passenger side. Be careful not to set them too high and blind oncoming traffic. Always test drive after adjustments. Some vehicles have a steering wheel-mounted roller for minor height adjustments, though its range is limited. The key is patience - make half-turn adjustments and frequently step out to check the changes.
If you encounter headlights being too low, I recommend checking the vehicle height sensors first. Many modern vehicles have these small square sensors installed on both front and rear suspensions. If they get dirty or misaligned, they can falsely report the vehicle's posture. For dirty sensors, simply wipe them with a damp cloth. If they're misaligned, refer to the repair manual to reset their positions. Incorrect headlight angles could also result from aging shock absorbers causing the vehicle body to sag, especially with weakened rear suspension springs—when the rear end sags, the front end tilts up. In such cases, adjusting the headlights is only a temporary fix; replacing suspension components is the real solution. Additionally, it's normal for headlights to lower when driving with a full load, as the automatic headlight system compensates for the height.
Driving to the repair shop for headlight adjustment is the most reliable solution. The technician will use a calibration device to align with the headlight inspection line, precisely measuring the angle of the cut-off line. They will also check if the headlight bracket is deformed—I've seen cases where rear-end collisions caused headlight displacement leading to misaligned projection angles. During adjustment, it's important to distinguish between single-light adjustment and dual-light synchronization. For headlights with adaptive front-lighting systems, a diagnostic computer must be connected to activate the adjustment mode. The entire process takes about 20 minutes, typically costing between 50-100 RMB. As a reminder, owners who have upgraded to HID lights should pay extra attention to proper adjustment, as scattered HID beams can be doubly hazardous.
