Brake Light Switch: All You Need To Know


The Brake Light Switch is a vital component of your car’s safety system, responsible for illuminating the brake lights when the brakes are engaged. 

You can keep your car safe and running smoothly by understanding the Brake Light Switch and how it works. 

In this post, we will go over all you need to know about the Brake Light Switch, from what it does to how to repair it.

What Is A Brake Light Switch?

The brake light switch is a crucial part of your car’s braking system. Pressing the brake pedal triggers the brake illumination and, if necessary, sends a signal to the internal computer instructing it to turn off the cruise control. 

The brake light switch also helps the computer determine how hard you are pressing on the brake pedal, which can help it adjust the braking system accordingly. 

Without a properly functioning brake light switch, your vehicle cannot correctly control its braking, resulting in poor performance and safety hazards.

How Does A Brake Light Switch Work

The brake light switch is a vital part of your vehicle’s lighting system and plays an essential function in protecting the safety of other drivers and you. The brake light switch is a small electrical device on the brake pedal assembly. 

When the brake pedal is pressed down, the switch activates, sending a signal to the rear brake lights to illuminate. 

This critical safety feature lets other drivers know you are slowing down or stopping. The brake light switch is attached to the wiring harness, so when you press the brake pedal, the current is directed to the rear brake lights, which will illuminate.

When you press the brake pedal, a plunger inside the brake light switch slides and makes contact with two metal contacts.  

This causes a circuit to be completed, allowing electricity to flow through the wiring harness and activate the brake lights. When you release the brake pedal, the plunger no longer contacts the terminals, and the circuit is broken, turning off the brake lights. 

It is important to note that the brake light switch only works when the ignition key is in the “on” position. Without this signal from the switch, your rear brake lights will not turn on even when you press down on the brake pedal. 

It is also essential to check your brake light switch regularly, as faulty switches can prevent your brake lights from working correctly.

How To Test Brake Light Switch?

How To Test Brake Light Switch
Credits: Max kegfire / Shutterstock

Simply tapping the brake pedal and looking at the lights will not reveal a faulty brake light switch. This exam could be deceptive.

The brake light switch can still be broken and must be replaced even if the brake lights function correctly.

Here is a step-by-step guide for testing the brake light switch on your car.
Use a multimeter that is calibrated in ohms. One pin has to have the positive and negative sides tapped.
A continuity reading under zero is required. If the measurement is greater than zero, the brake light switch has failed.

  • Assume the brake lights are in good condition.
  • Check the power of the brake light switch.
  • The wire connector that connects the brake light switch should be found.
  • Utilize a voltmeter to locate the power source.

Another factor that might keep a brake light on is a brake pedal stopper. Getting in touch directly with the brake light switch is
permitted if the brake pedal stopper is not depressed.

The light switch will continue to work even if the stopper degrades over time. If you wish to investigate this issue, the brake light switch should be adjusted. If the brake light stopper becomes broken, replace it and push the brake light switch against the brake stopper while adjusting.

When To Replace A Brake Light Switch

Replacing your brake light switch is an integral part of regular vehicle maintenance. When it comes to brake light switches, you should replace them when they fail or wear out. This typically happens after a few years of driving but can also occur earlier, depending on your usage.

Common signs that it is time to replace your brake light switch include: your brake lights do not turn on when the brakes are applied, your vehicle’s check engine light is illuminated, or your brakes feel spongy and don’t seem to be functioning correctly. 

If any of these symptoms are present, then it’s likely time to replace your brake light switch. 

If you encounter any of these symptoms, it is essential to take action right away in order to ensure the safety of you and other drivers on the road. 

Be sure to use a high-quality replacement part designed specifically for your vehicle’s make and model. It is also essential to have a professional technician inspect your car’s brake system if the switch needs to be replaced.

Steps To Replace A Brake Light Switch

  1. First, locate the brake light switch. It is usually found in the engine bay near the brake master cylinder.
  2. Disconnect the battery to ensure there are no electrical shocks when working with the brake light switch. 
  3. Remove the switch from its housing by unscrewing or unclipping it.
  4. Install the new switch in the same position and the same way as the old one. Make sure it is firmly secured before moving on. 
  5. Connect the wires from the switch to the wiring harness. Make sure they are firmly connected and secure.
  6. Test the new switch by pressing on the brake pedal a few times and observing if the brake lights come on. If they do not, then the switch may need further adjustment or replacement.
  7. Reconnect the battery and test the brake lights again to make sure they are working correctly.
  8. Finally, reattach the switch to its housing and double-check that it is securely fixed in place before putting everything back together.

Is There A Fuse For The Brake Light Switch?

Yes, there is a fuse for the brake light switch. It is typically located in the power distribution center, which can be found either under the dashboard or tucked away underneath your vehicle’s hood. 

The brake light system fuse is used to protect the wiring and other components of the brake light system from overloading due to a short circuit or another electrical fault. If the fuse blows, it can prevent the brake lights from functioning correctly. 

It is essential to check the fuse regularly to ensure that it is in a good state. Replacing a blown fuse is simple and only requires a few essential tools. 

If you suspect the fuse may have blown, you should consult a professional technician who can diagnose the issue and ensure that your brake lights are in proper working order.

How Long Does The Brake Light Switch Last?

The lifespan of a brake light switch can vary greatly depending on the quality of the part, the amount of wear and tear it has been subjected to over time, and other factors, such as the environment in which it is used. Generally, though, brake light switches have a reasonably long lifespan. 

Most are rated for tens of thousands of cycles or more, with some lasting up to 100,000 cycles or more. 

In addition to their longevity, brake light switches are typically very reliable and are only prone to failure if they are damaged or worn out due to heavy use. 

The best way to increase the life of your brake light switch is to properly maintain it by ensuring that it is regularly cleaned and lubricated and that it is not subjected to extreme temperatures or harsh environments. 

If you take good care of your switch, it should last many years without significant issues.

FAQS

Where is the brake light sensor located?

The brake light sensor is typically located near the pedal, on the firewall, or beneath the dashboard. 

Depending on your vehicle’s make and model, the sensor may be tucked away behind some other component. It’s a small unit with two wires attached to it and looks something like a large resistor or an electrical component. 

The brake light switch may also be integrated into the brake pedal itself. When you depress the brake pedal, the switch triggers and turns on the brake lights.

In order to access the brake light switch, you will likely need to remove some panels under the dashboard or even take apart some of the dashboard components. 

Once you’ve located the sensor, you can check if it functions correctly by connecting a test light or voltmeter to it. You may need to replace the switch if it isn’t working correctly. 

To do this, disconnect the two wires attached to the brake light switch and unscrew it from its mounting bracket. Then, insert the new controller and connect the cables before screwing it back into place.

Can the brake light switch cause shifting problems?

Yes, it is possible for a faulty brake light switch to cause shifting problems. If the brake light switch malfunctions, it can create an electrical fault in the vehicle’s wiring system. This can disrupt the signals controlling the shift solenoid, which may cause the car difficulty shifting gears.

Additionally, a brake light switch that is not functioning correctly can cause false activation of the shift interlock solenoid, which will prevent the driver from moving the shifter out of Park. 

Therefore, if you are having shifting problems and you notice that your brake lights are not coming on or off when they should, it is essential to have the brake light switch checked and replaced if necessary.

Do brake lights need a relay?

The short answer is no. Brake lights do not need a relay. However, if you are installing a supplemental towed vehicle braking system that pushes or pulls the brake pedal, then a Brake-Lite Relay might be necessary. 

This type of system monitors the amount of braking power being applied to the towed vehicle and will activate the brake lights on the car/truck when it senses that the brakes have been applied. 

The Brake-Lite Relay is designed to keep the brake lights on until the brakes are released in the towed vehicle. 

This ensures that the driver behind you is aware that you are slowing down or stopping and can react accordingly, and if you are unsure if your supplemental braking system requires a Brake-Lite Relay, it’s always best to consult an expert.

What powers the brake lights?

The brake lights in your car draw their power from the battery, and this system is liable for sending an electrical signal to the brake light when you hit the brakes as the electricity is routed through a switch in the brake pedal, which is activated when the pedal is pressed down. 

This switch then sends a signal to the brake lights, turning them on. 

The power from the battery helps ensure that the lights are more bright to be seen from a distance. It also helps keep them illuminated for an extended period of time so that drivers behind you can react quickly.

Do brake lights turn on with a handbrake?

No, brake lights do not turn on when the handbrake is applied. When the handbrake is used, the brake light switch is disabled, and the brake lights are no longer illuminated. This is beneficial in some situations, such as when driving at night, so that the brake lights won’t dazzle any drivers behind you.

Can a faulty brake switch drain battery?

Yes, a faulty brake switch can drain the battery. When the brake switch shorts internally, it will cause the brake lights to remain illuminated even when the brake pedal is not being pressed. This will burn out the brake lights more quickly and draw power from the battery, leading to a parasitic drain. 

This can cause the battery to lose charge faster than usual or even be drained entirely in some cases.

To stop this from happening, you should regularly check your brake light switch for any damage or wear and tear. If the switch is found to be faulty, you should replace it as soon as you can to prevent it from draining your battery.

Can you fix a brake switch?

Yes, you can fix a brake switch yourself. You will need a few tools, including a Phillips head screwdriver, a flathead screwdriver, a set of pliers, and possibly a wrench. Begin by locating the switch, which is usually attached to the brake pedal arm or the bracket underneath it. 

Detach the screws that hold the switch in place and then carefully disconnect the electrical connectors from the switch. After removing the switch, you can use a flathead screwdriver to remove the plastic cover that protects the switch’s internals.

Also Read: Why Does My Car Shake When Braking – (How To Fix)

Conclusion

The brake light switch is a vital component of your vehicle’s braking system, and it is essential to be aware of when it needs to be replaced. Knowing when to replace the brake light switch will ensure your safety on the road and the safety of other drivers around you. 

If you have any queries or concerns about your brake light switch, consult a qualified mechanic to get the information and help you need. With the proper knowledge and parts, replacing the brake light switch is easy and will help keep your vehicle running smoothly.