If you’ve noticed your car’s headlights are either dazzling oncoming drivers or not striking the road quite right, it might be time to check their alignment. Proper headlight aim isn’t just about being considerate to other road users; it also affects your visibility and can play a part in passing your annual MOT. Here’s a practical guide to aligning your headlights at home. With a bit of effort, you can handle this yourself and enjoy safer night‑time driving.
Why Proper Alignment Matters
When your headlights are misaligned, the benefits of high‑quality bulbs and clear lenses are wasted. A beam that’s pointed too high can blind other drivers. One that’s too low or off‑centre may not light the road properly. Serious failures in alignment are among the most common reasons for vehicles failing the MOT headlight aim check.
On a day‑to‑day basis, correct alignment means you’re seeing further ahead with less glare, and other road users aren’t being unnecessarily affected. It’s a worthwhile check and adjustment that many drivers overlook.
When to Check or Adjust Your Headlights
You should check your headlight alignment when:
- You’ve replaced a headlight bulb or unit, as this can shift the aim
- Your car has been involved in a bump, collision or heavy load shift
- You’re preparing for an MOT or carrying out general maintenance
- You notice symptoms like other drivers flashing you, weak or uneven beam patterns, or a change in your car’s stance
What You’ll Need Before You Begin
You don’t need expensive equipment — just some basic tools and a bit of space:
- A flat, level surface such as a garage floor or driveway
- A light‑coloured wall or garage door
- Masking tape or chalk and a measuring tape
- A screwdriver or socket set to access the headlight adjustment screws
- Make sure your car is in its typical loaded condition: driver’s weight, normal fuel level, correct tyre pressures and typical suspension height
- Switch on your low beams for the process. High beam is not suitable for alignment checks
Step‑by‑Step DIY Headlight Alignment
- Park your car facing a wall and measure the height from the ground to the centre of your headlights. Mark this height on the wall using tape or chalk. Also mark the centreline of your vehicle if possible
- Reverse the car around 8 to 10 metres from the wall
- Switch on the low beam headlights and observe where the brightest part of each beam falls relative to your marks. The centre of each beam should fall just below the horizontal line and slightly left of the headlight centre for right‑hand drive vehicles
- Locate the vertical and horizontal adjustment screws on the headlight unit. Use your tools to adjust: vertical screws will raise or lower the beam, and horizontal screws will move the beam left or right
- Adjust one headlight at a time, covering the other if needed to prevent confusion. Make small adjustments and check the beam position each time
- Repeat the process on the opposite headlight
- Once you’re happy with the adjustment, take a short test drive at dusk or night on a quiet road. Check that your beam gives you a good view of the road ahead without blinding other drivers
Special Considerations & Common Mistakes
- Modern vehicles with LED or adaptive headlight systems may not be suitable for DIY adjustments and might require professional tools
- Tyre pressures and suspension height affect beam direction, so ensure these are correct before starting
- Clouded or scratched headlight lenses can reduce visibility even if the beam is properly aligned
- If you’ve replaced the headlight unit, check it is designed for right‑hand drive vehicles. Left‑hand drive units have different beam patterns and can cause dazzle
- If your adjustment screws don’t seem to respond, or your beam still looks off, don’t force anything — it may be best to consult a technician
Safe Driving & Legal Compliance
Correct headlight aim is an important part of both safety and legal compliance. Misaligned headlights are a common reason for MOT failure. Regular checks help ensure your car lights the road properly without dazzling others. After you’ve checked your alignment, it’s a good opportunity to inspect the rest of your lights including brake lights, indicators and fog lamps.
When to Call in the Experts
There are times when it’s better to let a professional take over. Call a technician if:
- Your vehicle has advanced lighting systems such as Xenon or LED modules
- You’ve had a major front‑end collision or a suspension overhaul
- The beam remains unstable or incorrectly aimed even after adjustments
- You can’t locate the adjustment screws or they’re damaged
Recap & Quick Checklist
Here’s a handy list to follow when checking your headlight alignment:
- Car parked on a level surface
- Tyre pressures checked and corrected
- Vehicle in typical loaded state
- Mark headlight and centre heights on the wall
- Reverse car to appropriate distance
- Switch on low beams
- Adjust vertical and horizontal screws
- Check beam position is just below the line and slightly left
- Test on the road
- Seek help if unsure
Taking just 20 to 30 minutes to align your headlights can significantly improve your safety, reduce the risk of dazzling other road users and help you pass your next MOT. If you’d prefer to leave it to the experts, the team at Windmill Garage is here to help. Book in today for a quick alignment check and let us make sure your lights are set for safe, confident driving.