Car How to replace a headlight or brake-light bulb
Car · Beginner
How to replace a headlight or brake-light bulb
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A blown bulb is often a short job if you can reach the holder and you buy the exact type printed in the handbook or on the old bulb. This is for a conventional replaceable bulb, not a sealed LED or xenon unit, and not anything that means taking the bumper off unless the handbook shows a simple, obvious route.
Your call
Go or no?
Fancy giving it a go, or would you rather call a garage? There’s no wrong answer.
Right then. Here’s the kit, then the steps.
No problem. We’ll show you how to find a local garage.
At a glance
Shop the full kit
You can pick up the items below as you need them. Prices vary by shop and country, so we have not invented a figure here — check the live price before you buy. Shop links go to a product search on a local store for your country.
All-in-one kit
There is not usually a single boxed kit for this job. Buy the items below as you need them, and skip anything you already have.
Before you start
Safety
Stop and get a pro: Do not work on airbags, the SRS loom, or anything high-voltage on a hybrid or electric vehicle. If the headlight or tail unit is a sealed LED or xenon assembly, or the handbook says the bumper or wheel-arch liner has to come off and you are not confident, stop and find a garage. Do not force clips on a brittle, hot or painted housing.
- Park on level ground, apply the parking brake, switch the ignition off and take the key out. Let a just-used headlight cool before you touch it.
- Wear gloves or use a cloth on halogen bulbs — skin oil can shorten their life and a hot bulb can burn you.
- Do not look directly into a lit xenon or LED lamp at close range.
- Never rest the car on a jack to reach a rear lamp. If you cannot reach it with the vehicle sitting on its wheels, that is a garage job.
Prep that is worth doing
- Read the handbook section for exterior bulbs. Note the bulb type (for example H7, H4, P21W) and which side has blown.
- Open the bonnet or the boot and see whether you can reach the back of the unit with your hands before you buy anything awkward.
- Buy the correct bulb, and consider replacing a pair of headlights together if one has failed and the other is the same age.
Tools and materials
Check the live price at a shop you trust. Typical prices on this site, where they appear, were checked in the UK and may be out of date. Do not invent or assume a figure from this table. Shop links go to a product search on a local store for your country.
| Item | Why you need it | Typical price | Shop link |
|---|---|---|---|
| The correct replacement bulb for your vehicle | The type is in the handbook and usually on the old bulb. The wrong cap will not seat, or the beam will be wrong. | check price | |
| Clean nitrile or cotton gloves | To keep oil off a halogen glass envelope, and to protect your fingers. | check price | |
| A small screwdriver or trim tool, only if a cover needs easing off | Some dust covers twist off by hand. Do not prise a housing that is not designed to come apart. | check price | |
| A torch | The back of a headlight is often a dark, tight space. | check price |
Shop this list:
Step-by-step
Match the bulb, get safe access, swap the holder without forcing it, and check the light before you close everything up.
Identify the failed bulb and the correct replacement
Switch the lights on (or press the brake) and walk around the car, or have a helper do that while you watch. Note whether it is a headlight, sidelight, indicator or brake light. Check the handbook for the bulb type and whether that lamp is a replaceable bulb at all.
Make the car safe and get to the holder
Park on level ground, apply the parking brake and switch everything off. For a headlight, open the bonnet and remove the rear dust cover if there is one, usually with a twist. For a tail or brake light, this is often through a boot trim hatch or by undoing a few screws on the lamp unit — only as the handbook shows.
Release the old bulb
Some bulbs twist and pull, some sit in a bayonet holder, and some are held by a wire spring clip. Note how the old one sits before you undo it. Ease it out without yanking the wiring. If a connector is tight, press the tab rather than pulling on the wires.
Fit the new bulb
Handle a halogen bulb with gloves or a cloth. Line up the tabs or the bayonet pins with the holder and seat it fully, then refit the clip or twist the holder to lock. Refit the dust cover so it seals — a loose cover lets water in.
Test before you tidy up
Switch the ignition on and test the light, including dipped and main beam, or the brake lights with a helper or a wall behind you. If the new bulb does not light, re-seat it and check the fuse before you assume the bulb is faulty.
If you cannot reach it, or the unit is sealed
Stop. Forcing a bumper off, or prising a sealed LED lamp, is how units crack and airbags or looms get damaged. Find a garage.
General guidance only. Check our disclaimer.
Common mistakes
- Fitting the wrong bulb type. It may go in loosely, sit at the wrong angle, or dazzle other drivers. Always match the handbook code.
- Touching a halogen bulb with bare fingers. Oil on the glass can make it fail early. Wipe it with methylated spirit if you already have, or fit another bulb.
- Leaving the dust cover off. Water and dirt will sit in the lamp and rust the contacts.
- Working under a car on a jack to reach a rear lamp. That is a no. Use a garage if access needs the vehicle raised properly.
- Ignoring a warning light after a “successful” swap. If the dashboard still reports a lamp fault, the bulb may not be seated, or the unit may need a garage diagnostic.
FAQ
Should I change both headlights at once?
If one halogen headlight has failed and the other is original, many people replace the pair so the colour and brightness match. It is not a legal requirement, just a sensible option.
The bulb looks fine but it does not light.
Check the fuse and the connector, and that the holder is fully locked. Corrosion on the contacts is a common cause. If the fuse blows again, stop and find a garage — there may be a short.
My car has LED headlights. Can I swap a ‘bulb’?
Usually no. Many LED and xenon units are sealed assemblies. Replacing them is typically a garage or specialist job, and some need coding after a swap.
A policeman or a tester flagged a light. Do I have to use a garage?
Not if you can replace a simple bulb yourself and the light then works. If the unit is cracked, the beam is aimed wrongly, or you cannot get to it, use a garage so the car is legal to drive.
Would rather not DIY? Find a local garage
If the unit is sealed, the bumper has to come off, a warning light stays on, or you simply cannot reach the holder, a garage or mobile mechanic will finish it without broken clips.
We may earn from shop links, at no extra cost to you. Disclosure