Is it possible to use LED bulbs for brake lights?

Susan Fernandez February 02 2022

How do brake lights work?

As a car owner or just for interest's sake, how do brake lights work? When a car's brakes are applied the brake pedal presses a hard rubber pad against a metal disc. This transfers hydraulic pressure to activate two small pistons that clamp together and pressurize the brake fluid in the master cylinder to slow or stop the car.

The piston on top goes from being pressed down to getting pushed up by a spring, forcing the pressured brake fluid through holes in a one-way valve which redirects it back into another chamber along with more fluid from extra chambers until there is enough pressure to force out of tiny holes in the second piston and reach both light switches.

The left switch activates all three bulbs while the right operates just #1 and #3. Brake lights use two filaments instead of three.

Why are there two brake lights?  

Brake lights use two filaments instead of the usual three, #1 for left turn signal and tail light, #2 for right turn signal and tail light. When one filament is off, the other is on. This saves electricity since only one bulb has to be lit at a time.

Thus when you step on the brakes both brake lights come on giving others behind you an idea that something's wrong or your car's turning/slowing down. Normally if it was just one working it could cause confusion when braking because drivers won't know if they need to slow down or stop until they're close enough to tell what reflected light signals actually mean.

The amount of electricity used by the two brake light filaments is a fraction of a normal bulb whereas a high-powered brake light uses a standard wattage to produce greater reflectivity.

There are three types of brake lights: incandescent, neon and LED. The most common combination is an incandescent bulb with a neon bulb acting as a reflector for additional brightness. So which type would be best for your car?

LED's advantages/disadvantages

A major advantage in using led lights instead of other bulbs, such as incandescent or neon, is that LED bulbs don't get hot when activated for prolonged amounts of time, unlike their counterparts. However, they do cost more than other bulbs so you'd need to weigh up if it's worth it or not.

In the UK, the number plate light is also called a brake light as it's situated on your rear bumper and tells those driving behind whether you're slowing down or stopping by getting brighter when activated. Since they use incandescent bulbs though, they can explode if placed under high pressure. This is why some cars have two of them for redundancy purposes in case one fails.

The number plate lights are often used as a reference point to tell how efficient your brake lights are working so look around for any areas that seem too bright or dim compared to others and check with a mechanic to see what might need adjusting/replacing. Sometimes it's just dust build-up but changing the bulb occasionally can help prevent this from happening.

The brake light switch is usually found on the top of the brake pedal. If you find it's not working properly, you can get a replacement at most car garages or order one online. You might also want to consider getting an automatic headlight sensor if your car doesn't already have one because they're handy for switching headlights on during the day when it's raining or dark out since sensors are able to detect moisture in the air and act accordingly.

Do LED tail lights need any extra components?

Since LEDs don't need filament, there are no extra components needed for brake lights or number plate bulbs so they can be installed to replace whatever type of bulb your car uses.

However, different brake systems require different types of LED bulbs. If you're not sure whether or not they'll work with your particular system it's best to ask the retailer first before purchasing. They should be able to help out with any questions you might have about color coding (not all colors are compatible) or overall compatibility. Make sure whatever bulb you choose is for the correct wattage as well or else it could cause issues down the line if too bright/dim for what your car needs.

That is why depending on your vehicle you might need some additional components if you want to use LED lights, otherwise, the switch could become faulty after a while. Among such components, you may need to install CANBus to your vehicle so the system could automatically regulate the correct load for different functions of LED lights.

CANBus is a network that transfers data between electronic devices, sensors, and the components they serve. It was developed by Robert Bosch GmbH in 1983 as an open bus standard to allow microprocessor-based automotive control systems from different vendors to easily communicate with each other and work together more efficiently.

As you may see, previous knowledge of car parts and electronics is not required but definitely helpful when installing LED lights yourself. If you choose to use a professional service, they will guide you through all necessary steps and even provide free installation support if something goes wrong or just doesn't work.

That being said, LED bulbs cost a lot of money so if you have a reliable car with few requirements to use them, it may be better to stick with stock parts even if their originality cannot be verified.

How bright should the brake lights be?

When using LEDs for brake lights, the brightness should be checked by a professional. However, they may be dimmed manually if chosen to offer less danger for other drivers and pedestrians. Indeed, the power of certain bulbs might cause blindness in oncoming traffic if too bright. It's also not good if your lights are dimmer than your neighbor's because it means you're not standing out as much or signaling others about how quickly you're coming to a stop.

Do LED brake lights affect other cars? In most cases, no because each vehicle has its own voltage requirements for appropriate operation. Once installed, LEDs should work normally without any problems but sometimes it takes some time until they get recognized by the system and adjust their power levels accordingly depending on how much light is required.

How to install LED to the brake lights correctly?

First, you need to find out what kind of system is installed in your car and what voltage it operates on. Most modern systems with CANBus are using 12V but some models might have the same voltage for brake lights as turn signals or high beam headlights so it's important not to mix up wires.

It should be pretty straightforward because each wire has its own color. If you are building a custom LED circuit though, remember there are negative sides as well so red-wire positive with black-wire negative won't work unless extra resistors are added.

However, if things become complicated there are plenty of retailers who can help over the phone with queries about compatibility between their products and your vehicle's electronics. They'll ask about the make, model, year, and other details to make sure everything fits together.

You can find more detailed information on the packaging or on the retailer's website about what kind of system works best with your bulb type. If you're not sure, it's always better to ask first before making a purchase. As already mentioned, most retailers offer phone support so if something doesn't fit together or work as intended they'll help you figure out what went wrong so you won't have to deal with time-consuming returns and shipping issues.

What are the possible difficulties with installation?

When you have already chosen the LED bulbs for the brake lights, it's time to get your hands dirty. First, the stock bulbs should be removed so you can start working with bare wires. After properly preparing them for installation, LED lights are usually attached directly to the wires without any additional mounting brackets or housings.

It may take some trial and error before getting everything right but if there is no power coming out of either end when installing new bulbs then the circuit might be badly built or something in between is not working at all. If that's the case, don't hesitate to call a professional because this job requires specific training when involving electronics.

However, LED lamps themselves may also cause problems due to their sensitivity and make sure they are installed in proper conditions like temperature and humidity. They should also be tested daily for proper operation to avoid accidents on the road.

If you are building a custom LED circuit that operates differently from the original system, then you might need an electronic converter box that will regulate the power supply without triggering an error report or switch off your brake lights altogether.

That being said, most modern cars have CANBus systems which mean they'll easily recognize new bulbs and adjust their power levels accordingly so everything is safe to use. With this kind of technology, dimming becomes very simple because it's done automatically without any extra effort on your side. However, if there is no CANBus circuit installed in your vehicle then check with the retailer whether LEDs are compatible with its system before attempting installation.

What about other bulb types for the brake lights?

If you are not like for LED bulbs, there are also high-performance halogen or xenon bulbs for brake lights available. They require the installation of additional mounting brackets and connectors but in general, the process is very similar.

However, there are also other types like HID which might be suitable if you already have LED lamps installed in your car's headlights because the matching ballasts will power them up. If everything goes well, these bulbs work even better than factory ones thanks to bright blue light that really makes vehicles visible on dark roads, especially at higher speeds.

LEDs are always more expensive than ordinary incandescent or halogen lights but they are extremely cost-efficient over time because LED lifetimes are measured in tens of thousands of hours. LEDs may require a slightly different approach when installing them. If you're not sure, it's always better to ask instead of trying something that might not work or be dangerous in general.

The same goes for custom circuits but even if everything goes well then there is still a chance of getting electrocuted so make sure the power supply cannot cause a short circuit that will switch on your brake lights unintentionally. It can also lead to serious damage to other parts of your vehicle so avoid touching damaged components until you figure out what happened.

Finally, LED lifetime depends heavily on how often they've been used and under what conditions. Even with proper use accidents are still possible especially when water gets into electronics which is why your brake lights should be checked every time after washing.

Necessary steps:

  • Make sure to properly ground and power up all the parts of your circuit.
  • Provide enough space for wires so they do not get damaged or reach temperatures that might damage other components in your vehicle's electrical system. 
  • LED lamps may cause problems due to high sensitivity. They should also be tested daily for proper operation to avoid accidents on the road.
  • Other car components like mirrors must be adjusted accordingly to work with new bulbs installed on the stop lights because these are separate circuits that work independently from each other.

Final words

You can use LEDs for brake lights, but you must have a proper grounding and power supply before installation. Install these in your vehicle's stoplight circuit only after making sure that other components are adjusted accordingly. You should also test all the bulbs daily to avoid accidents on the road.