Brake Lights Switch
If your car brake lights suddenly stopped working, it'll be hard for you to tell whether you have a problem with your brake electrical circuit, brake lights orbrake lights switch. You may start replacing components unnecessarily, trying to fix your brake lights. Instead, you can use a simple test that could help you troubleshoot the switch. You don't need special skills for this procedure. All you need is a simple test light and a few minutes of your time.Locate the switchOn most vehicles, the brake light switch is mounted on the arm of thebrake pedalor a small bracket near the pedal. Another common mounting place is the brake master cylinder. This cylinder mounts on the brake booster, a drum-like component on the driver's side of the firewall inside the engine compartment.After locating the brake light switch on your car, probe the two wires that connect to the back of the switch connector using a test light. This light is similar to an ice pick. However, thetest lighthas a clear handle and a light bulb mounted inside the handle. The bulb connects to the pick and an electrical wire that extends through the other end of the handle. At the end of this wire you'll find an alligator clip.Troubleshooting the switchTo test the brake switch, hook the test light clip to the metal frame or to a metal bracket under the dashboard. If your switch is inside the engine compartment, clip the light to a bolt on the engine or a mounting bracket. Insert the test light pick through the back of the brake switch connector so that the tip of the pick touches the metal terminal of one of the wires inside the connector. Then probe the other wire on the same connector.The test light should glow as you probe one of the wires but not the other one. If the test light doesn't glow as you probe either one of the wires, there's no voltage reaching the brake light switch and you need to repair the circuit for the switch to work.Now, depress the brake pedal or have a helper depress the brake pedal for you. Probe both wires on the brake light switch connector again, using the same procedure. This time, the test light should illuminate as you probe each wire. This means your switch is working properly. If the test light only illuminates on one of the wires, you need to adjust your switch so that it is properly mounted on the connector, or the switch is broken and you need to replace it.Vehicles with cruise control come equipped with two brake switches or a switch with four wires. If you need to find the switch or figure out the wires that connect to the brake switch on one of these models, check the service manual for your specific vehicle make and model. You can buy this manual at most auto parts stores. However, it's possible that your local public library has a copy in the reference section.
