How to change a car headlight bulb – a step-by-step guide

The lights on your car are the safety feature you never really think about. They ensure you can see – and be seen – at night, and give other road users vital information about which direction you’re travelling.

Making sure your car’s lights are in full working order is a legal requirement, too. If they’re not working or poorly adjusted, you’ll risk being stopped by the police.

Chances are you’ll rely on your car’s lights more in the depths of winter than at any other time of the year; because of the long nights and the likelihood of visibility-sapping rain, mist or fog, lights are essential. 

To check they work, flick your side lights, dipped and main beam headlights on to make sure they all function, and don’t forget your fog lights, indicators and rear lights. You might need some help to check reverse and brake lights. Give them all a wipe if they’re covered in road grime – and run a cloth over your number plates while you’re at it.

How to change a headlight bulb

Bulbs can be really easy or really tricky to replace. YouTube is a great place to find out how to change yours, although some high street car spares shops will swap them for a few pounds.

For the most part, the method you’ll use is more or less the same.

Changing a headlamp bulb: a rough guide

- Open your car’s bonnet to gain access to the back of the headlamp
- Check you’re able to get your hand to the access panel. In some cars access is great; other cars require the skills of a contortionist. Remember that in some cars you may need to remove other parts which are in the way. These range from dust covers to batteries and airboxes, or even front grilles or entire front bumper assemblies. We strongly recommend you do your homework before you break out any tools
- You may need to remove a dust cap to gain entry to the back of the headlight. Once there, you’ll need to remove the plug which connects to the bulb

- Once the plug is off, you’ll need to remove the retaining clip to release the bulb. This can be one of the trickiest parts of the job, because they can be stiff and hard to reach
- Withdraw the bulb; you may need to twist it to free any retaining tabs from their slots. You’ll need to remember where the tabs locate when installing the new bulb.
- Check the old bulb and new one side by side to double-check you have the correct one
- Locate the new bulb into the headlight unit and secure with the clip, then reconnect the plug
- Before replacing any dust covers or other car parts you’ve removed, check the new bulb works
- Check that the bulb is correctly aligned. With the car facing a wall, make sure that the beams from both headlights reach the same height up the wall. If the beam from the bulb you have replaced is markedly higher or lower than the other headlight, you may have fitted it incorrectly. If in doubt, you may need to visit a garage.

Types of car headlight bulb

There are three main types of headlamp bulb, but each of these are available in multiple different sizes and fitments, and may be specific to your car. You should always check your car’s manual to make sure you buy the correct one.

Halogen bulbs are the type traditionally used in cars. Much like an old household bulb, they use a filament which glows brightly when current is passed through them. They often have a slightly yellow tinge. They are usually used in older cars, but are cheap to buy.

High Intensity Discharge (HID) bulbs are sometimes called xenon bulbs. These use xenon gas and an electric arc to general a bright white light. They’re more expensive than halogen bulbs, but are brighter and more efficient. These are only suitable for use in cars whose headlights used them from new.

LED headlights are increasingly commonplace. Headlight units are usually constructed from a number of light-emitting diodes (LEDs) and can be exceptionally bright. They consume very little electricity, but are generally considered sealed units so replacing faulty LEDs can be a tricky business.

Note that LED bulbs are not usually suitable for headlights that weren’t originally designed to use them, and they could give rise to an MOT fail when used in a car originally fitted with Halogen bulbs.

What Car?’s guide to driving in winter

How to check a car battery
How to check a car tyre: pressures and tread depth explained
How to replace windscreen wipers – and check screenwash
How to check your car’s antifreeze
What to carry in your car during winter
How to drive in winter
What to do if you get stranded
Should I fit winter tyres?

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