Here’s How To Adjust Your Headlights At Home
Don’t be that person with the cockeyed headlights.
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If you’re an aggressive driver, you may be used to seeing middle fingers and brights flashed at you, but for most of us, those responses from other drivers can be quite alarming. If it’s happening at night, it might be because you're annoying other drivers with the way your headlights are aimed.
Even the most expensive cars with the neatest headlights will eventually need to have their eyes adjusted. It’s not just a safety issue for you—seeing the road is important and all, but a poorly-aimed headlight combined with a dirty windshield could completely blind an oncoming driver and cause an accident.
What Does It Mean To Adjust Your Headlights?
Throughout time, the bumps and bangs that come with daily driving can knock your headlights off-kilter, causing them to wander away from an alignment that actually helps you see in low-light conditions. When this happens, you’ll need to adjust the headlight units, which are enclosed and mounted on either side of your vehicle’s nose.
Modern headlight enclosures are separate from the body of your vehicle and are mounted with screws. There are also adjustment screws on the headlight units that allow vertical and horizontal adjustment. Using a fixed point on a wall, vehicle owners can aim their headlights using the adjustment screws and some simple measurements.
Do All Headlights Need Adjusting?
At some point, it’s likely that all headlights, regardless of the technology behind them, will need adjustment. Even self-leveling or adaptive headlights can end up out of line from time to time. The adjustment process may be slightly different for modern LED units, or those with self-adjustment features, but there will eventually come a time when even the most advanced headlights will need to be adjusted.
How Do I Know If My Headlights Need To Be Adjusted?
A good way to know if your headlights are out of alignment is if other drivers are constantly honking or flashing their brights at you. Even without annoying every other person on the road, you can tell if your headlights need adjustment by looking at the road ahead of you. Are both lights aimed forward to illuminate the road, or are you flashing lights into every house you pass as you drive through your neighborhood? If one light isn’t hitting the road in front of you by being aimed too high, too low, or to one side, it’s time to adjust your headlights.
Headlight Adjustment Safety
Take this job seriously and make sure you get it right. You’re not just making your own life easier at night, you’re reducing the chances of blinding or distracting another driver.
- If you’re sure your car needs a headlight adjustment and are unable to do so for one reason or another, take it to a shop as soon as possible. Don’t ignore the problem.
- You’ll be in and out of your car and will need to move it during this process, so be sure you’re working in a spot where you won’t be in traffic while trying to adjust your headlights.
- Your hands and face will likely be in and around your engine bay, so be sure to wear safety glasses and mechanic gloves.
Everything You’ll Need To Adjust Your Headlights
Grab this equipment before you start.
Organizing your tools and gear so everything is easily reachable will save precious minutes waiting for your handy-dandy child or four-legged helper to bring you the sandpaper or blowtorch. (You won't need a blowtorch for this job. Please don’t have your kid hand you a blowtorch—Ed.)
You’ll also need a flat workspace, such as a garage floor, driveway, or street parking. Check your local laws to make sure you’re not violating any codes when using the street because we aren’t getting your ride out of the clink.
Here’s How To Adjust Your Headlights At Home
Let’s get started with the simple stuff first.
Prepare Your Vehicle
If you’re a packrat, or just love to carry around a week’s worth of clothing and supplies in your car at all times, you’ll want to remove as much unnecessary weight as possible before beginning this process. If your trunk is full of old motor oil containers (we hear you, classic VW owners), take them out so that your car’s stance is as level as possible.
It’s also important to note that some vehicles have interior controls to level or adjust headlight settings. If your vehicle has a separate interior system for adjusting headlight position, make sure it’s in a neutral or middle setting to aim the lights properly. Consult your service manual for specific instructions on your vehicle.
Park In Front Of Target Wall
You can do this test in front of a garage door, or any solid wall (though textured garage doors might have surfaces that could distort the light). Light-colored surfaces and solid surfaces (not brick or stone) will give you the best results here. Park 10-15 feet away from the wall and make sure that your car is parked on a level of a surface as possible. Performing this test while parked on a hill or a bumpy surface won’t do much good.
Turn On Headlights And Observe Position
Turn on the vehicle’s regular beam headlights. Don’t activate high beams or fog lights for this test. Using your tape, form a cross in the center of each headlight beam on the wall. It’s normal for the driver’s side light to be slightly lower than the other. This is to avoid shining lights into oncoming traffic as the car travels down the road.
Back Vehicle Away From Wall
This is one situation where your trusty eyeball measurements are going to yield poor results. Use your tape measure to scope out a distance that is exactly 25 feet from the wall. As you’re backing up, try to do so in a straight line.
- Once backed up, turn off the vehicle and headlights, and pop the hood.
- Make sure the hood is secured in an upright position before you start digging around. Locate the headlight enclosures at the front of the engine compartment.
- Remove any trim pieces that are covering the headlight units. Be sure to refer to your vehicle’s maintenance manual for pointers here.
- The adjustment screws should be located on the top and the side of the headlight enclosure, one to adjust the vertical position and the other to adjust horizontal position.
Adjust Headlights Accordingly
You’ll want to block one headlight while adjusting the other. Use a tarp or old sheet so that you can focus on one light at a time. If it’s helpful, you can have a friend sit inside and turn the headlights on and off to help you get the right aim for each unit.
- As you’re adjusting the vertical position using the top screw, observe the light’s position on the wall ahead of you. The vertical position of the most intense part of the light should be even with the horizontal tape line you made on the wall.
- Similarly, as you’re adjusting the horizontal position, aim to move the beam so that it’s aligned with the vertical tape line you made.
Go For A Drive
Try to test the lights out in a non-threatening environment, such as an empty parking lot or a quiet street. Drive slowly and observe your headlights’ positioning. If one or both lights are out of alignment, you’ll need to repeat this process.
FAQs About Adjusting Headlights
You’ve got questions, The Drive has answers!
Q: How Far Should Your Headlights Shine While on Low Beam?
A: According to the National Highway Traffic Safety Administration (NHTSA), the distance illuminated by low beam headlights is about 160 feet. Modern LED and HID lighting systems may perform differently, but you’re not going to be able to blast out light hundreds of feet ahead of you without grabbing a few middle fingers or a ticket along the way.
Q: How Far Do High Beams Shine?
A: High beams reach quite a bit further than low beams, at between 300 and 400 feet. Again, your headlights may perform better or worse, depending on the features of your vehicle.
Q: How High Should Your Headlights Be Aimed?
A: When your car is parked 25 feet away from the wall you’re using to align them, use a tape measure to find the distance from the ground to the center of the light beam. Then measure the distance from the ground to the center of your headlight unit itself. The area illuminated should be around the same height as, or even a bit lower than, the headlight unit.
Some vehicles have a nifty level built right in so that you can visually observe the position without having to park and measure.
Q: My Headlights Are Dim. What Can I Do?
A: If your headlights are dim, there could be a few things going on. You may have a failing bulb or lighting unit, which will require a repair or replacement, depending on the type of light. Your battery or alternator could be failing and not delivering the correct level of power to each light.
Or, your headlight lens may just be dirty or cloudy. As cars age, the plastic that is used in headlight housings can become tarnished, yellowed, or cloudy looking. You can clean it up using a simple headlight restoration kit.