Brake Light Switch replacement & repair made easy

How does a brake light switch work?

The brake light switch’s main job is to activate the brake lights whenever you press the brake pedal. It works much like a basic on/off switch. When your foot is off the pedal, the switch is in the "off" position, and the brake lights stay off. But as soon as you press the brake pedal, the switch’s plunger is released, allowing its internal contacts to meet. This completes the electrical circuit and turns the brake lights on, letting other drivers know you’re slowing down or stopping.

While many brake light switches are fairly simple, often designed as a push-in-and-twist type that sits just above the brake pedal, some vehicles have more complex setups depending on their design and electronic systems. Whether basic or advanced, all brake light switches perform the same critical function: making sure your brake lights work exactly when they’re needed.

Where is the brake light switch located?

In most cars, the brake light switch is located under the dashboard, just above the brake pedal arm. It’s mounted on a small metal or plastic bracket so that when you press the pedal, a plunger on the switch moves, completing the circuit and turning on your rear brake lights.

Look for a compact block with one or two electrical connectors attached, positioned where the pedal lever meets the under-dash framework. When you gently press the pedal, you’ll see or feel the switch plunger moving in and out, that confirms you’ve found it.

Because this switch not only controls your brake lights but also affects systems like cruise control disengagement and automatic-transmission safety locks, keeping it in good condition is essential for safe and legal driving. If your brake lights stay on, don’t illuminate, or your cruise control stops working, it’s best to have a qualified mechanic inspect or replace the switch.

What does a brake light switch replacement job involve?

When a mechanic replaces the brake light switch, they follow a simple but precise process to make sure your brake lights operate correctly and safely:

• The mechanic will ask about the issues you’ve noticed—such as brake lights staying on or not working—and may run a quick electrical test to confirm the switch is at fault.
• The brake light switch, pedal mechanism, and nearby wiring are visually inspected for damage, corrosion, or loose connections.
• If the switch is faulty, it’s removed and replaced with a new manufacturer-approved part that matches your car’s specifications.
• The area around the pedal and switch mount is cleaned to remove dust or debris that could interfere with movement. The new switch is adjusted so it activates precisely when the pedal is pressed.
• The mechanic tests the brake pedal several times to confirm the lights illuminate and go out correctly, then verifies the operation during a brief test drive.

How do I know when I need a brake light switch replacement?

If your brake light switch is faulty, your car may show several noticeable symptoms, including:

• All Brake Lights Not Working – If none of your brake lights turn on when you press the brake pedal, even after confirming the bulbs and fuses are fine, it’s likely due to a faulty brake light switch.
• Brake Lights Stay On – If your brake lights remain lit even when you’re not pressing the pedal, the switch may be stuck in the “on” position or not releasing properly.
• One Light Still Working – If only one brake light isn’t working while the others are fine, it’s probably not the switch at fault. That’s more likely to be a bulb or wiring issue.

If you notice any of these symptoms, it’s important to have the brake light switch inspected and replaced if needed to make sure your vehicle remains safe and road-legal.

How much does a brake light switch replacement cost?

A brake light switch replacement typically costs around £80 on average. However, the final price can vary depending on your specific car make and model, as well as the parts your manufacturer recommends for the replacement. Some vehicles may require more specialised or higher-quality components, which can affect the total cost. Use our free price estimator tool to find out what you could save by having your brake light switch replaced by ClickMechanic!

What is the difference between a brake light switch and a brake pedal switch?

Although they sit side by side on your brake pedal, the brake light switch and brake pedal position switch (or sensor) have very different jobs:

• Brake light switch: This is a simple on/off electrical switch that activates when you press the brake pedal. Its main job is to power the rear brake lights and disengage the cruise control system. In short, it’s the safety signal that tells drivers behind you when you’re slowing down.
• Brake pedal position switch (sensor): This more advanced sensor sends a variable signal to your car’s ECU (engine control unit), telling it exactly how far the brake pedal is pressed. Modern systems use this data for features like hill-start assist, idle-speed control, engine braking, and driver-assist technologies such as stability or adaptive cruise control.

Many newer cars include both switches: one numbered two-pin unit just for your brake lights, and a separate three-pin or multi-pin sensor for the engine and safety systems.

If your brake lights won’t turn on or stay on, or your cruise control cuts out unexpectedly, it’s best to have a qualified mechanic test both components. That ensures the correct switch is replaced, restoring proper lighting and electronic braking functions without unnecessary repairs.

What does a ClickMechanic brake light switch replacement quote cover?

Unless otherwise stated, the quote will cover:

• The cost of the brake light switch
• Coming to you
• Fitting of the parts
• Disposal of the old parts (unless you request to keep them)
• VAT (if applicable)
• 12-month parts and labour warranty

Can a mobile mechanic replace the brake light switch?

Yes, a mobile mechanic can replace your brake light switch without needing to take your car to a garage. This job doesn’t usually require any heavy equipment or a car lift, which makes it perfect for a mobile repair service. The mechanic will come to your home or workplace, inspect the brake light system, and if the switch is faulty, they’ll replace it right there on the spot.

After fitting the new switch, the mechanic will test your brake lights to make sure everything is working as it should. It's a quick and straightforward job for a professional, and it can save you time and hassle by avoiding a trip to the garage.