7440/7443 LED Bulbs - Turn, Reverse, Brake & Tail Lights

What Is a 7440 LED Bulb?

A 7440 LED bulb is a single-function automotive bulb used in selected turn signal, reverse, brake, tail, and daytime running light positions. The original 7440 halogen bulb is commonly rated at 12V and 21W and may also be identified as W21W or T20.

A 7440 bulb normally provides one lighting function and one brightness level. It may operate as a reverse light, turn signal, brake light, or tail light, depending on the vehicle and lighting position.

7440 vs. 7443 LED Bulbs: What Is the Difference?

7440 and 7443 bulbs belong to the T20 wedge-base family and look similar, but they have different electrical functions.

A traditional 7443 dual-filament brake light bulb provides two brightness levels. In a compatible brake and tail light position, the lower level operates as the tail light. The brighter level activates when the brake pedal is pressed. A 7443 LED bulb provides these functions electronically instead of using two filaments.

A 7440 bulb generally provides only one function. Because the contacts, wiring, and socket configuration differ, 7440 and 7443 bulbs are not universally interchangeable.

How to Choose 7440 and 7443 LED Bulbs by Color and Position

First, confirm whether the original bulb is a 7440 or 7443. Then check the lighting position and socket. The same bulb number may be used in different positions on different vehicles.

After confirming fitment, choose the color required for that position:

• White: Commonly used for compatible LED backup and reverse light bulbs or DRL lights. Use white only behind a clear lens and where the vehicle requires white light.
• Amber/yellow: Commonly used for compatible LED turn signal bulbs and parking lights. An amber bulb may be used behind a clear or amber lens when specified for the vehicle.
• Red: Commonly used for compatible LED brake and tail light bulbs. Use red where the vehicle requires red light output.
• White/amber switchback: Designed for compatible positions that combine a white parking light or DRL with an amber turn signal. The bulb, socket, and vehicle wiring must support both functions.

Check the product specifications for socket compatibility, installation space, and possible hyperflash. Do not assume that every 7440 or 7443 LED bulb will work in every lighting position.

Will 7440 or 7443 LED Bulbs Fit My Vehicle?

Confirm the original bulb number and lighting position before ordering. A standard 7440 bulb supports one lighting function, while a standard 7443 bulb can support two functions or brightness levels.

Also check whether the vehicle uses a standard or CK-style socket. These sockets may look similar, but their contact layouts differ. Use the Automotive Bulb Finder to check the bulb size for your vehicle.

LED turn signal bulbs may cause hyperflash because they draw less current than halogen bulbs. Depending on the vehicle, a compatible load resistor, LED flasher relay, or CANBus solution may be required.

Most SEALIGHT LED bulb packages include a decoder. It may help with flickering, dashboard warnings, or bulbs that do not turn on. If a compatibility problem remains, contact SEALIGHT customer service for troubleshooting and a compatible decoder at no additional cost.

Why Choose SEALIGHT 7440/7443 LED Bulbs?

SEALIGHT offers 7440 and 7443 LED replacement bulbs for a range of compatible exterior lighting applications.

1. Multiple colors and functions: Choose from white, red, amber/yellow, and switchback bulbs for compatible reverse, brake, tail, turn signal, and DRL positions.
2. Clear, responsive illumination: LED bulbs illuminate quickly and provide a crisp appearance in compatible exterior light housings.
3. Convenient installation: The compact wedge-base design supports straightforward installation in compatible 7440, 7443, W21W, and W21/5W applications.
4. Decoder and compatibility support: Most packages include a decoder. Troubleshooting and a compatible decoder are available at no extra cost if a decoding issue occurs.
5. Vehicle fitment assistance: Use the Automotive Bulb Finder or contact customer service to confirm the bulb size, lighting position, and socket before ordering.
6. Convenient shipping and returns: Orders qualify for free shipping within the continental United States and 90-day easy returns.