Fog Light change & replacement made easy

What does a fog light unit do?

In the UK and across Europe it is mandatory for the car to have at least one (working) rear fog light, to warn traffic of your presence when they are closing in on you from behind. Some cars are also equipped with front fog lights, either as standard or as an optional extra, which help you to see the road ahead more clearly in thick fog.

How do fog lights work and what are the components?

Fog lights are very similar to other lights, only they have a brighter intensity bulb. Under normal conditions, these bulbs are too bright for other road users, so are switched off, otherwise the driver can face a penalty fine.

They are switched on manually by the driver either from the light control stalk or via a separate switch. An additional warning lamp will appear on the dashboard reminding the driver that they are switched on.

The fog light itself will either be a separate unit or part of the rear light cluster, but usually the front ones are single units on their own.

How do you know when there is something wrong with your fog light unit?

Usually a visual check will show whether the light unit has been cracked or damaged, but you may also see water inside it behind the lens.

When should you consider a fog light unit replacement?

• If your fog light lens has been cracked, it will generally require replacing otherwise you will get water ingress and it will cease to work. More often than not, the unit is a sealed one and the whole unit will be replaced.
• If you have replaced the bulb and it still doesn’t work or you are replacing the bulb frequently.
• It is a legal requirement to have a working rear fog light and is of course an MOT failure point should it not.

How common is a fog light unit replacement?

Rear units are often at the extremities of the vehicle and are therefore prone to accidental damage during parking.
Front fog lights are usually mounted low down and therefore receive frequent strikes from stones and other road debris. Therefore front fog light replacement is a common task.

How can I extend the lifetime of my fog light units?

The only thing you can do is be careful while reversing to ensure you do not damage the rear light units, but there is little you can do to help the front ones, its down to luck!

What happens during a fog light unit replacement?

• Mechanic will inspect the fog light unit for damage
• If necessary, the mechanic will replace the broken fog light unit.
• Mechanic will advise if any other parts need to be replaced.
• Mechanic will test the light(s) to ensure the lights work properly.

How much does a Fog Light Replacement cost?

The cost of replacing a fog light depends on your car and what parts your car's manufacturer recommends using for the replacement. Find out what you could save by having a fog light replaced by ClickMechanic, by selecting your car at the top of this page!