Brake lights are integral to proper driver-to-driver communication on the road. If your brake lights have stopped working, it’s a real cause for concern. In this article, we’ll take a look at the different brake light tests you can do to make sure everything’s in good working order.
Why You Should Test Brake Lights
As we’ve mentioned, brake lights relay important information to other drivers on the road. They show when your vehicle is slowing down or stopping, and the milliseconds they save are crucial in any sort of emergency. Testing your brake lights can be as simple as having a friend or family member stand behind the vehicle to watch if they turn on when you step on the brakes. If the brake lights turn on, you’re good to go. If they don’t, or if your vehicle’s check brake system light is on, it might be time to visit a trusted mechanic.
Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.
Pro Tip: For some vehicles, you need to make sure the key doesn’t have to be on while checking the brake lights.
Tips for Testing and Repairing Brake Lights
The process of testing and repairing your brake lights can vary between being beginner-friendly and expert-only levels of difficulty. We’ll break down some of these processes in this section so you can judge for yourself whether you can conduct these repairs in your garage.
Blown Brake Light System Fuse
If no brake lights are working at all on your vehicle, it’s less likely that they burned out at the same time. A blown brake light system fuse is the most likely culprit. A blown fuse is a quick fix that you should be able to do on your own.
Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.
Pro Tip: The problem is that if the fuse blew once, it’s likely to blow again, which means your problem is likely deeper than just a blown fuse. If it only blows every two or three days, that’s even more dangerous because you might not know the brake lights aren’t working.
You might want to disconnect the vehicle’s battery before proceeding (although few people actually do this because the fuse are made to be “hot swappable”).
Check your vehicle’s fuse boxes for the brake light system fuse, which you can usually find marked on the fuse box lid, or there will be a diagram in the owner’s manual if you haven’t thrown it away. Keep an assorted box of fuses in your vehicle for such a time as this; they don’t cost much and it’s smart.
Look and see if the fuse’s translucent cover isn’t so translucent anymore or has some other form of damage. You can also grab a test light from an auto repair store if you want to test the fuse more thoroughly. Usually though, signs of damage should be enough to indicate it’s time for a change. Unplug the old fuse and plug in a new one with the same amperage, reattach the battery, and you should be good to go. You can use a set of needle nose pliers or plastic tongs to make handling the fuses easier.
Blown fuses can indicate a problem somewhere else in your vehicle’s electrical system, so you might want to bring your vehicle in for a routine inspection.
Bad Brake Light Switch
If the brake light fuse isn’t to blame for all of your vehicle’s brake lights going out at once, then it’s time to take a look at the brake light switch. This switch connects the brake light circuit to the vehicle’s electrical system. It has two wires, one of which controls the incoming power while the other controls the outgoing power. You can find the marked switch near the brake pedal. Use a test light to see if the switch is receiving and releasing power.
Should the test light indicate that the switch isn’t working, you’ll need to remove the wiring harness, remove the switch from the brake pedal linkage, and insert a new switch with the same specifications as the old one.
Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.
Pro Tip: Make sure you know how to do this right. Some switches are adjustable and some require disconnection of the brake master cylinder pushrod from the pedal. Do this wrong and you might end up with more problems.
This repair is more complex than simply replacing a fuse because there might be other connections you need to sever when testing the switch. You might want to leave it to a professional.
Burnt Brake Light Bulb
If only one brake light is not working, it’s time to check on the bulbs. Removing a brake light bulb can be a hassle depending on your vehicle. Some models have more complex bulb systems than others. Generally, you can get to the bulbs by going through either your vehicle’s trunk or its fender, removing the casing or bulb trim, and unscrewing the bulb. Once you do manage to get your hands on your vehicle’s brake light bulb, you can check if the filament inside its casing is blackened or broken. A crack on the bulb is also a sure sign that the bulb is bad. Wedge-type bulbs can look just fine and still not work, so there’s that too.
If you see no issue with the bulb, but the rest of the system is working fine, it’s possible the bulb is just burnt out. Replace both bulbs if you find one has burned out. If one light’s gone, the other is likely to follow soon. Remember to purchase the right type of bulb and wattage according to your vehicle’s manual.
Faulty Brake Light Socket
The brake light socket is another possible point of failure that you can check on while you have the bulbs out. If you see signs of corrosion on the socket, try cleaning it using electrical contact cleaner. If the brake light still doesn’t work, try testing the socket using the test light. Press the light against the contacts. If two of the three contacts light up, it should mean the socket is fine. If one or no contacts light up, it might be time to have a trusted mechanic replace the socket. You can test the wires behind the socket as well, but this will require you to push past the insulation behind the socket, and we don’t recommend doing so if you aren’t familiar with electrical work.
It’s illegal to drive with no brake lights, so once you notice your brake lights aren’t working, you need to address the issue immediately. The last thing you want is to cause a bad roadside accident. At the very least, you now know where to start if you want to check your brake lights to see what’s wrong.
Keep Reading: Related Posts
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.
