Checking your car lights: headlights, bulbs and alignment
In autumn and winter you often drive in the dark, in the rain or in fog. Good lighting is then essential: you need to see the road clearly, and other road users need to see you in time. You often do not notice a faulty bulb yourself. In this article, XCS Automotive in Merchtem explains how to check your lights quickly, why your headlight alignment matters and what the roadworthiness test looks at.
Why lighting matters so much
Lighting is about two things: seeing and being seen. With weak or poorly aligned headlights, you notice obstacles and pedestrians later. A faulty brake light or indicator makes it harder for others to predict what you are doing. That is why faulty lighting is unsafe and a point the roadworthiness test checks.
Check your lights yourself in five minutes
This is best done at dusk, in front of a garage door or a wall. Ask someone to help if possible.
- Dipped beams and sidelights: switch them on and walk around the car.
- Main beams: switch them on and check that both headlights shine brighter.
- Indicators: left and right, front, rear and on the mirrors or wings. Switch on the hazard lights too.
- Brake lights: ask someone to press the brake pedal, or look at the reflection in a window or door. Do not forget the third brake light.
- Reversing light: with the ignition on and reverse engaged.
- Fog lights: front, if your car has them, and the rear fog light.
- Number plate light: often forgotten, but mandatory.
If an indicator flashes much faster than normal, there is usually a faulty bulb on that side.
Your headlight alignment
Headlights set too high dazzle oncoming drivers. Headlights set too low light up too short a stretch of road ahead of you. Even a small deviation makes a big difference at a distance.
The headlight levelling control
Many cars have a control to adjust the height of the headlights. If you drive with a full boot, passengers in the back or a trailer, the front of the car rises. You compensate for that with the levelling control. Your owner's manual says which setting goes with which load. Some cars do this automatically.
Alignment after a repair
After an accident, replacing a headlight or work on the suspension, the alignment may have shifted. Have the headlights realigned in that case.
Halogen, xenon or LED
With halogen bulbs, you can replace a bulb yourself on many cars, although access is difficult on some models. Preferably replace bulbs in pairs, so both sides shine equally brightly.
Xenon lights work at high voltage. Have them replaced by a professional. LED lighting is often integrated into the headlight unit. If it fails, a larger part sometimes has to be replaced. We look at what is needed and give you a price in advance.
Also watch out for bulbs that are not approved for road use. A bulb that does not match the headlight can dazzle and will not pass the inspection.
Dull or yellowed headlight lenses
On many older cars, the plastic headlight lenses become dull or yellow over time. As a result, less light reaches the road. Depending on their condition, they can be polished or replaced. Feel free to ask us what is possible for your car.
Lighting and the roadworthiness test
During the roadworthiness test, the lights and signalling are checked, as is the headlight alignment. Faulty bulbs or misaligned headlights are among the common remarks. So have your car checked before the test. On our page pre-inspection check you will find a checklist. Read more about the new inspection rules in our article on the vehicle inspection in 2026.
What do we do?
At every minor service we check the lighting. We replace faulty bulbs and, where needed, align the headlights. If a lighting warning appears on the dashboard while all bulbs work, we read out the fault. Diagnosis costs €83 excl. VAT per hour, repairs €75 excl. VAT per labour hour. You get a 1-year warranty on the work carried out.
Extra lighting on commercial vehicles
Commercial vehicles sometimes need extra work lights or signalling. These must be fitted and connected correctly, so they do not interfere with the vehicle's electronics. More on our page van equipment.
Frequently asked questions
Can I replace a bulb myself?
With halogen bulbs this is possible on many cars. Use the right type of bulb. Xenon and LED are best left to a professional.
Why does my indicator flash faster than normal?
There is usually a faulty bulb on that side. Have it replaced.
How do I know if my headlights are aligned correctly?
If oncoming drivers often flash their lights at you, or you see the road poorly, have the alignment checked.
Is the lighting checked during servicing?
Yes, at every minor service we check the lighting.
Have your lights checked?
Book your appointment online via make an appointment or call Jorne on 0471 46 40 17 or Quinten on 0470 56 61 21. You will find us at Stoofstraat 43 in Merchtem, open Monday to Friday from 8 am to 6 pm and on Saturday from 10 am to 5 pm. Anywhere in Merchtem, we collect your car and bring it back free of charge.