Modern vehicles contain many electronic parts. Through which all the functions of the vehicle work properly and the vehicle runs smoothly. But over time, problems with electronic parts and wiring components are natural. Similarly, there is a malfunction in the brake light switch in the electronic components of the vehicle, due to which the brake light does not light up when the brake pedal of the vehicle is pressed.
In this article, we will learn in detail about the symptoms, causes, location, and how to replace a bad brake light switch.
What Is A Brake Light Switch?
Often used in vehicles, brake light switches, also called stoplight switches, this are an essential component of the vehicle’s safety system. It plays an important role in illuminating the rear brake lights of the vehicle when the brake pedal is pressed.
When the driver applies pressure to the brake pedal, the brake light switch connected to the brake pedal is activated. The brake light switch completes the electrical circuit to light the brake light, allowing electricity to flow to the brake light. As a result, the brake lights illuminate, alerting drivers behind the vehicle to slow down or stop.
Brake Light Switch Location
The location of the brake light switch may vary depending on vehicle makes and models. In most vehicles, the brake light switch is usually located near the brake pedal, which is attached to the brake pedal arm.
When you press the brake pedal, it activates the switch and completes an electrical circuit to light the brake lights, which illuminate the brake lights at the rear of the vehicle.
Bad Brake Light Switch Symptoms
Common symptoms of a bad brake light switch may include brake lights not turning on, brake lights staying on constantly, ABS system warning lights illuminating, cruise control warning lights illuminating, trouble starting the engine, or the gear selector not moving.
1. Brake Lights Not Working
Whenever we press the brake pedal of a vehicle for the brakes, the brake light switch at the bottom of the brake pedal is depressed and completes the electric circuit and the brake light is on.
But if for some reason the brake light switch is damaged, or the input/output circuit is interrupted, the brake light will not turn on when you brake. You can get the vehicle replaced or repaired by an electrician. If the brake light is not on, it can cause serious problems while driving.
2. Brake Lights On Continuously
If there is a fault in the brake light switch of a vehicle. It can also be a symptom of a bad brake light switch, which can cause the brake light to stay on when you press and release the brake pedal.
3. ABS System Warning Light On
Some vehicles use an ABS braking system, in which the brake light switch plays an important role. The brake light switch sends a signal to the ABS braking system unit to indicate the pressure applied by the driver on the brake pedal, which causes the ABS braking system to operate successfully.
If there is a fault in the brake light switch, the ABS warning light will appear in the vehicle’s cluster meter from the ABS system unit. This is a symptom of a bad brake light switch, which will cause the ABS braking system to not function properly.
4. Cruise Control Warning Light On
Cruise control has become an important function in vehicles with modern technology. This function also works properly through the brake light switch, as there is a wire going from the brake light switch to the cruise control module, which sends a signal about the braking condition and the position of the vehicle.
And the cruise control unit, according to the signal, controls the vehicle speed. But sometimes the vehicle’s brake light switch sends a bad or incorrect signal, and the cruise control module warning light may show in the vehicle’s cluster meter.
5 Engine Starting Problems
This function is commonly used in push button start vehicles, vehicles with keyless entry. The company also assembles the engine starting function of many vehicles with the brake system. This function is inbuilt for safety so that the vehicle cannot be driven when the brakes are applied.
So that the engine, clutch assembly, and braking system of the vehicle are not damaged due to the mistake of the driver. In such vehicles, a wire from the brake light switch is wired to the vehicle’s engine starter motor unit, so that the vehicle does not receive electric input to the engine starter motor when the brakes are activated. This function is also provided by the clutch pedal in many vehicles.
6 Gear Selector Not Moving
Automatic transmissions are used in many vehicles. The transmission gear selector of these vehicles operates via ECU power command, which is linked to the brake light switch for input and output of brake status and status signals.
If the brake pedal is applied by the driver, the automatic transmission gear selector will not function, and if the bad brake light switch is unable to send an output signal, the gear selector will not function. This could also be a sign of a bad brake light switch.
Causes Of A Bad Brake Light Switch
Possible causes of a brake light switch failure include breakage of the switch’s plastic piston, worn or broken switch springs, a corroded brake light switch, and the switch not receiving input power.
1. Switch Plastic Piston Break
The brake light switch has a plastic piston. that moves in or outside when the brake pedal is pressed by the driver. Then the piston of the brake light switch presses inward., to which the electric circuit of the brake light is connected, which turns on the brake light. And when the pressure is released from the brake pedal by the driver.
Then the brake light switch piston returns to the same position and breaks the electric circuit, and then the brake light stops burning. But sometimes the piston of the brake light switch breaks or gets worse. One of the reasons for this could be a faulty brake light switch.
2. Switch Springs Sitting or Breaking
The brake light switch has a metal spring inside to push the plastic piston out, which pushes the brake light switch piston outwards when the brake pedal is under pressure. and the piston comes back to its disconnected position when this spring breaks or loses its power. Then the piston of the brake light switch may be stuck inside, and the brake light may be on continuously.
3. Corroded Brake Light Switch
Sometimes, a vehicle standing for a long time causes carbon to enter the brake light switch, which is unable to connect the input and output of the power supply to the brake light switch.
Therefore, the brake light switch does not work properly and the brake light of the vehicle does not turn on and at the same time, the functions related to the brake light switch are also interrupted.
4. Switch Not Receiving Input Power
The brake light switch provides the input power supply to each vehicle. But sometimes the power supply to the brake light switch is not able to come on due to a faulty or disconnected input supply wire, due to which the brake light switch stops working. This could also be caused by a blown fuse on the brake light switch.
How To Fix Bad Brake Light Switch?
- Check the power input and output supplies to fix the brake light switch. Also check the brake light switch fuse. If the input and output lines of the power supply are correct and the brake light switch is still not working. Then take out the brake light switch and check.
- If the brake light switch is worth repairing, it can be repaired by an expert vehicle electrician. If the brake light switch cannot be repaired, replace the brake light switch with a new one. If going to replace brake light switch, always use company genuine brake light switch.
How To Brake Light Switch Replacement
Replacing the brake light switch in vehicles is a simple process. For this, follow the step-by-step process mentioned.
- Gather Tools and Materials: Before replacing any vehicle’s brake light switch, you must gather the necessary materials and tools. Such as a new brake light switch, a screwdriver, wrench, or pliers, wire connectors, and electrical tape.
- For safety: Before replacing the brake light switch, make sure the vehicle is turned off and the key is removed from the ignition. For this, you can also disconnect the battery.
- Find the brake light switch: Usually, vehicles will have a brake light switch located near the brake pedal, which will have a wire connected to it.
- Disconnect the wires: Carefully disconnect the wires from the bad and old switches. To remove any retaining clip, you will need to apply pressure. Use pliers or a screwdriver to do this.
- Remove the old switch: Often, the brake light switch is fitted to the brake pedal with a retaining nut or clip. So use appropriate tools to remove it.
- Install the new switch: Install the new switch in the same location as the old switch and tighten it to the brake pedal arm with the retaining nut or clip. Connect the wires to the new brake light switch. Make sure the wires are connected securely.
- Test the brake lights: If you disconnected the battery cable, reconnect it. To check if the brake lights are on, have someone press the brake pedal, and you will see the brake lights. If it lights up correctly when you press the brake pedal, the replacement has been successful.
Brake Light Switch Replacement Cost
Typically, a brake light switch can cost anywhere from $80 to $150. The labor of an electrician or mechanic to replace a brake light switch can range from $10 to $30.
However, the cost of replacing the brake light switch with a new one depends on the vehicle model and the mechanic’s labor rate.
Q. How do you know if your brake light switch is bad?
For this, you can find out by looking at the symptoms mentioned below. Your vehicle’s brake light switch is faulty.
- Brake light not working
- Constant Brake Lights
- ABS system warning light on
- Cruise Control Warning Light On
- Engine starting problem
- Gear Selector Not Running
Q. Where is the brake light sensor located?
The brake light switch can be seen as part of the brake-pedal assembly of the vehicle. These brake light switches can be pulled or pushed. You can find this switch on the bottom of the dashboard or near the top of the pedal lever.
Q. How much does it cost to fix a brake light?
The labor cost for an electrician or mechanic to replace a brake light switch can range from $10 to $30. which may increase depending on the model of the vehicle.
Banty is the owner of Autorepairszone.com & is also a vehicle mechanic by profession. We have almost 12 years of experience in the field of automotive repair, and we strive to provide you with accurate information about vehicle malfunctions and repairs based on our experience.