How does the brake light switch work?

Asked By: Irvin Trabadelo | Last Updated: 15th June, 2020
Category: automotive auto safety
4.9/5 (68 Views . 26 Votes)
The brake light switch serves two major functions. First, it turns on the brake lights when a driver presses the brake pedal. Second, it sends the signal to the vehicle computer that brakes are applied. In most cars, the brake light switch is installed right above the brake pedal.

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Similarly, it is asked, how does a brake light circuit work?

Brake lights serve a simple but important function -- they warn drivers behind you when you're slowing down. At the other end is the brake switch, where the pedal presses down and creates contact that completes the circuit. The system draws power from the car's battery.

Secondly, how do you fix a brake light switch? How to Replace a Brake Light Switch

  1. Open the driver door of the car and kneel down inside so that you can see and reach the underside of the dash, where the pedals connect.
  2. Remove the two or four Phillips-head screws that are behind the brake pedal and that hold the electrical cover in place.
  3. Remove the cover.

Regarding this, how do you know if your brake light switch is bad?

One of the symptoms commonly associated with a bad brake light switch are brake lights that stay on at all times. If the brake light switch shorts internally it may cause the brake lights to stay illuminated, even when the pedal is not being pressed.

What happens when brake light switch fails?

A faulty brake light switch can cause many problems. If a switch is bad, the brake lights won't operate and the transmission shifter will not come out of "Park" position. In cars with a push-button start system, a faulty brake light switch can cause the vehicle not to start.

19 Related Question Answers Found

Where is the brake light fuse located?

Like all fuses, the brake light system fuse can be found in the power distribution center, which is under the dashboard or tucked away underneath the hood.

How can I check my brake lights by myself?

It's simple enough to test your brakes. Just have a friend stand behind the car while you step on the brake pedal and have him or her tell you if everything looks OK. If you're working alone, rig up a mirror or lay a broomstick on the pedal and tuck it into the seat, then walk behind the car and look for yourself.

Is there a fuse for brake lights?

Blown Fuse
If your lights don't illuminate on either side and your brake light switch is good, then the next thing to check is the brake light fuse. Locate your vehicle's fuse box, which is usually under the hood or on the kick panel inside the passenger compartment.

Do tail lights and brake lights use the same bulb?

Tail light and brake light are the same bulb. Tail light works, brake light doesn't.

How much does it cost to replace a brake light switch?


The average cost for a brake light switch replacement is between $70 and $94. Labor costs are estimated between $42 and $54 while parts are priced between $28 and $40.

What can cause my brake lights not to work?

When your brake lights don't work, it is usually because of a blown fuse, a worn-out or broken brake light switch, or a burned-out light bulb.

What makes brake light come on?

Low brake fluid/Worn brake pads
Roberson says in most cases, a brake warning light indicates low brake fluid, which is often a result of worn brake pads. “As the pad wears, the brake caliper piston extends further to keep the pad in contact with the rotor,” he says. No fluid, no brakes.

What is a brake pedal position sensor?

The ACDelco GM Original Equipment Brake Pedal Position Sensor monitors the movement or position of the brake pedal to directly activate the brake, brake lights, and turn off cruise control if applied, and is a GM-recommended replacement for your vehicle's original components.

How do you check brake lights?

What To Do
  1. Turn the ignition on and make sure the vehicle is not in gear.
  2. Open the car door.
  3. Put one end of the floor brush/ mop on the brake pedal.
  4. Push down until the brake is engaged and then lock in place so that the pedal remains pushed down.
  5. Go around the back of your car and check the lights.

What is a stop light switch?


The brake light switch, also known as the stop light switch or brake/stop lamp switch, activates the red brake lights on your rear tail lights when you press the brake pedal.