TAIL & BRAKE LIGHT BULBS

A tail light normally illuminates when the vehicle’s parking lights or headlights are turned on. Its purpose is to make the rear of the vehicle visible to other drivers in low-light conditions.

A brake light illuminates more brightly when the brake pedal is pressed. It warns drivers behind you that the vehicle is slowing or stopping.

Some vehicles use one bulb for both functions. In that case, the bulb may operate at two brightness levels. Other vehicles use separate bulbs, LEDs, or lamp sections for the tail and brake functions.

Because rear lamp designs vary so widely, always identify the exact function before ordering a replacement bulb.

Single-Filament and Dual-Filament Bulbs

Traditional incandescent rear lighting may use either a single-filament or dual-filament bulb.

A single-filament bulb typically performs one lighting function. For example, it may serve only as a brake light or only as a turn signal.

A dual-filament bulb contains two filaments that can operate at different brightness levels. One filament may provide the lower-intensity tail light while the second produces the brighter brake or turn-signal function.

This is why two bulbs that appear similar may not be interchangeable. Their bases, contact arrangements, wattage, and number of electrical circuits can differ.

Common Tail and Brake Light Bulb Sizes

Rear combination lamps use many different automotive bulb sizes. Depending on the vehicle, common examples may include:

• 1156
• 1157
• 3156
• 3157
• 7440
• 7443
• 3057
• 3357

These are examples only. Your vehicle may use a different bulb, an integrated LED assembly, or a configuration-specific rear lamp.

Always use the bulb number listed for the exact position on your vehicle. A physically similar bulb may have different contacts or electrical characteristics.

For more information about bulb numbering, visit the Automotive Bulb Size Guide.

Why Some Bulbs Have Similar Numbers

Automotive bulb families often contain several closely related bulb numbers. For example, 3156 and 3157 bulbs may look similar, but they are designed for different electrical functions. The same is true for 7440 and 7443.

One version may be intended for a single-intensity circuit while another supports two brightness levels or multiple functions.

Do not assume that a similar bulb number means the bulbs can be substituted for one another. Match the exact application whenever possible.

Red Bulbs and Clear Bulbs

Rear lighting systems may use either a colored bulb behind a clear lens or a clear bulb behind a colored lens.

For example, a vehicle may use a clear incandescent bulb inside a red tail lamp housing. Another vehicle may use a red bulb behind a clear or lightly tinted section of the lamp.

If the original bulb is colored, replacing it with a clear bulb may change the appearance or function of the lamp. When choosing a replacement, check both the bulb number and the required color.

This is especially important when considering LED alternatives, because LED bulbs are often sold in specific colors such as red, amber, or white.

LED Tail and Brake Light Bulbs

LED replacement bulbs are available for many traditional tail and brake light bulb sizes. They can offer fast illumination, lower power consumption, and a different appearance compared with conventional incandescent bulbs.

However, simply matching the bulb base does not guarantee complete compatibility with every vehicle.

Possible LED compatibility issues include:

• Bulb-out warning messages
• CAN bus monitoring
• Incorrect brightness between tail and brake functions
• Electrical polarity
• Physical clearance inside the lamp housing
• Different light distribution
• Rapid flashing if the circuit also functions as a turn signal

For this reason, ALBulbs keeps the original bulb fitment separate from any LED Alternative shown in your results.

The LED option is an additional replacement possibility and does not change the standard bulb fitment identified for the vehicle.

Before converting to LED, read our LED Compatibility guide and LED Retrofit Guide.

Combination Tail, Brake, and Turn Signal Bulbs

Some rear bulbs perform more than one function. A single bulb may serve as a tail light and brake light, while another design may combine tail, brake, and turn signal functions within one rear lamp assembly.

This makes the exact bulb specification especially important. A replacement must have the correct contacts and intensity levels for the circuit it serves.

If the wrong bulb is installed, one lighting function may fail even though another appears to work normally.

Center High-Mount Stop Lights

The center high-mount stop light, sometimes called the third brake light, is normally mounted higher than the main rear brake lamps.

Depending on the vehicle, this lamp may use one or more replaceable bulbs or an integrated LED assembly.

Do not assume that the third brake light uses the same bulb as the left and right brake lamps. Check the specific position in your ALBulbs results before ordering.

Factory LED Tail Light Assemblies

Many modern vehicles use integrated LED rear lamp assemblies. In these systems, the tail or brake light source may not be a conventional removable bulb.

If an integrated LED section stops working, diagnosis may involve the LED module, circuit board, wiring, connector, body control system, or complete lamp assembly.

If your vehicle is equipped with factory LED tail lamps, inspect the assembly before purchasing a replacement bulb that may not apply to your vehicle.

Why Your Vehicle May Have More Than One Rear Light Configuration

Rear lamp equipment can vary by trim level, body style, market, production date, or optional appearance package.

For example, a base trim may use conventional incandescent bulbs while a higher trim of the same vehicle uses LED tail lamps. Sedans, hatchbacks, wagons, trucks, and SUVs sharing a model name may also use different rear lamp assemblies.

When ALBulbs provides a configuration option, choose the version that best matches the lighting equipment installed on your vehicle.

Understanding Your ALBulbs Fitment Results

ALBulbs may display a verification label beside a tail or brake light fitment result.

• Not Verified — The fitment has supporting information, but ALBulbs does not currently have enough qualifying confirmation to assign a higher verification level.
• Verified — The fitment has stronger supporting evidence, such as qualifying manufacturer information or confirmation from multiple sources.
• Cross-Checked Verified — The fitment has a higher level of independent supporting confirmation.

A Not Verified result does not automatically mean the fitment is incorrect. It means that additional confirmation is recommended before purchasing.

Visit Understanding Your Results for more information about ALBulbs verification labels and fitment notes.

Check the Existing Bulb Before You Buy

Whenever possible, remove or inspect the existing rear light bulb before ordering a replacement.

Check the bulb number, number of contacts, base design, color, and whether the bulb appears to be single- or dual-intensity.

This is especially important when:

• Your vehicle has multiple rear lamp configurations
• Your result is marked Not Verified
• The lamp assembly appears aftermarket
• The vehicle has been modified
• You are switching from incandescent to LED

If the installed bulb does not match the ALBulbs result, investigate the difference before ordering or forcing a replacement into the socket.

Replace Tail or Brake Light Bulbs in Pairs?

When one incandescent bulb fails after many years of use, the bulb on the opposite side may have accumulated a similar amount of operating time.

Replacing both bulbs at the same time can help maintain a more consistent brightness and color between the left and right sides.

Before ordering a pair, verify that both sides use the same bulb number and that neither lamp assembly has been replaced with an aftermarket unit.

What If a New Bulb Still Does Not Work?

If replacing the bulb does not restore the light, the problem may be elsewhere in the circuit.

Possible causes can include a damaged socket, corrosion, wiring problem, poor ground, fuse, connector issue, switch, control module, or another electrical fault.

If multiple rear lights stop working at the same time, it may be especially important to inspect the electrical system rather than assuming several bulbs failed simultaneously.

Tail and Brake Light Fitment Matters

Rear lighting is a safety-critical part of the vehicle. The correct bulb must provide the appropriate brightness, color, electrical function, and fit for the lamp assembly.

Using the wrong bulb can result in poor visibility, incorrect brightness, warning messages, malfunctioning brake or turn-signal functions, or a bulb that does not fit securely in the socket.

ALBulbs is designed to help connect the vehicle, lighting position, bulb number, supporting fitment information, and available replacement options so you can make a more informed choice.

Find Your Tail & Brake Light Bulbs

Ready to look up the rear lighting for your vehicle? Use the ALBulbs Vehicle Finder to select your year, make, model, and available configuration.

Your results may include tail lights, brake lights, rear combination lamps, and other lighting positions along with bulb numbers, verification information, standard replacements, and available LED alternatives.

Find My Bulbs

If your vehicle uses a different tail or brake light bulb than the one shown in ALBulbs, visit Report Incorrect Fitment. Providing the vehicle, lighting position, and actual bulb number can help us review and improve the fitment information.

Find the right bulb. Every time.