On most vehicles, the brake light system is a simple circuit, which includes a switch, light bulbs or lamps, a fuse, and the wiring that connects these parts. When the brake lights on your vehicle fail to work, there are several things that could be the cause: a blown fuse, a worn-out light switch, a burned out light bulb, and so many more problems. Here are some things you can do if your brake lights do not work:
IF ONE OR MORE BRAKE LIGHTS FAIL
If one or more of your brake lights suddenly stop working, it is relatively easy to fix. Here’s what to do:
- Check the condition of the light bulbs.
- Remove the light bulbs. To do this, push each one down and turn it counterclockwise, then pull it out.
- Take a careful look at each bulb. It could be that the bulb itself has failed and simply needs to be replaced. In this case, make sure to replace it with bulbs of the same type and wattage.
IF NO BRAKE LIGHTS WORK
If none if the brake lights work, you might have to take a critical look at the components that affect the entire circuit (the fuse, brake light switch, turn light switch etc.).
- The first thing to check in this case is the fuse. Here’s what to do:
- Find the location for the fuse. For this, consult the car owner’s manual. When you find it, remove the fuse panel lid and look for the descriptions of each fuse, to find the one you are looking for.
- When you find the fuse, pull it out. When you do that, you can tell if the fuse is blown by looking at the fuse element.
- If your fuse is blown, you need to replace it. Make sure you do so with another one of the same amperage, which you can tell by looking on the fuse case.
- You might also need to check out what caused the fuse to blow, which might be a short circuit.
- If your fuse is not the problem, check the brake light switch. You might want to have a repair manual for your vehicle model at hand for this. Here’s what to do in this case:
- First, find the switch in your car. Once again, you should refer to your car owner’s manual. After finding the switch, look for the electrical connector for the switch.
- Now, check the switch for a current. Do this by connecting a test light to a good ground under the dashboard, then connecting it to a power source. Now, back probe the terminals on the connector without unplugging it. If your brake light switch is good, your test light should come on when you probe one of the terminals.
- If the test light does not come on, the power side of the circuit might have an open circuit or a short circuit. Locate the issue using your car repair manual. After this, you can either adjust the brake light switch or replace it.
- On some vehicles, the brake light circuit is part of the rear section of the turn signal circuit. If you still can’t see what’s wrong with your brake lights after the above steps, check the turn signal switch. Here’s how it is done:
- Find the wiring diagram for your turn signal switch on your repair manual, then locate the wire that goes from the brake light switch to the turn signal switch.
- Next, try to connect to the electrical connector. Consult your repair manual for this.
- Depress the brake pedal to activate the brake light switch, then back probe the brake switch wire at the signal switch connector using a test light. The test light should glow. If not, there is an open circuit in the wire between the signal switch and the brake light switch.
- Depress the brake pedal again, and back probe the terminals that carry current from the signal switch to the left and right turn signal lights. If the test light does not glow, the signal switch is not working.
Note that you should only carry out any of the above steps if you feel comfortable doing DIY work on your car. If not, you might find it more prudent to take the car to the mechanic for proper attention.