The 7443 bulb is a dual-filament halogen bulb supporting two brightness levels (tail + brake or DRL + signal) for better nighttime visibility, rated at 21W/5W OEM power, while the 7440 bulb is the single-filament version rated at 21W for dedicated turn, brake, or reverse functions. Although physically identical, 7443 and 7440 differ electrically: 7443 can operate in a 7440 socket, but 7440 cannot provide a dual-intensity function in a 7443 circuit.
This collection covers both 7443 and 7440 LED bulbs, the LED upgrades of the OEM 7443 dual-filament bulb and 7440 single-filament bulb, both defined by the W3x16q wedge base with four electrical contact pads for 12V automotive signalling circuits. These bulbs are factory-standard across rear lighting systems in many vehicles, where the 7443 bulb provides dual-intensity output (21W brake / 5W tail) and the 7440 bulb provides single-intensity 21W signalling or reverse output.
The LED replacement bulbs convert the filament light source to solid-state LED emitters while preserving the OEM wedge-base geometry and contact orientation required for direct socket compatibility. LED versions operate at ~3–8W equivalent power draw, significantly lower than halogen, and are engineered with CANbus load-matching resistors or driver IC circuits to maintain correct electrical behaviour in modern vehicles with bulb-monitoring ECUs.
Electrical & Functional Attributes
- Voltage: 12V automotive system compatible
- Base: W3x16q wedge push-in fitment
- Circuits:
- 7443 = dual-circuit (tail + brake / DRL + signal)
- 7440 = single-circuit (turn/reverse / brake)
- Halogen wattage: 21W (7440), 21W/5W (7443)
- LED equivalent: ~3–8W typical
- Brightness range (LED): ~500–1800+ lumens, up to ~12000 lm in reverse kits
Because the 7443 LED bulb retains dual-channel driver circuitry, it can reproduce OEM tail-and-brake brightness separation, while 7440 LED bulbs provide single-channel high-output signalling or reverse illumination. Although physically identical, the bulbs are not functionally interchangeable in all circuits: 7443 can operate in many 7440 sockets, but 7440 cannot replicate dual-intensity 7443 operation.
Lighting Functions Covered in This Collection
- Brake & Tail (7443 red LED)
Dual-brightness output preserving OEM low-power tail and high-power brake illumination.
- Turn Signal (7440/7443 amber LED)
Directional signalling using ~2000K amber emitters for DOT/ECE compliance and high daytime visibility.
- Reverse Light (7440 white LED)
High-lumen 6000K white output (up to ~12000 lm kits) improves rearward illumination and camera clarity.
- Parking / DRL (7443 white LED)
Low-intensity running light or DRL circuits in rear or front housings.
- Switchback (7443 white/amber)
Dual-mode LED where the white running light switches to amber turn signal in clear-lens housings.
Optical & Housing Compatibility
7443/7440 bulbs are easy to install in reflector-based rear lamp housings or lens-filtered assemblies. Because halogen filaments emit 360° omnidirectional light, LED replacements in this category use multi-chip radial emitter arrays to replicate filament light distribution and ensure full reflector fill. This prevents hotspots, dark zones, or beam imbalance in the tail and brake functions.
CANbus & Hyperflash Control
LED bulbs draw less current than halogen bulbs, which can trigger hyperflash or bulb-out warnings in vehicles with monitoring ECUs. Many bulbs here integrate built-in load resistors or CANbus drivers calibrated to approximate 21W halogen electrical signatures, maintaining normal blink rate and dashboard status. Sensitive vehicles may still require external resistors. If you still face any issue and need assistance follow our guide that takes you through common issues with 7440 & 7443 bulbs and how to solve the issues easily.
Technology Variants in This Collection
- Red 7443 brake/tail LEDs with integrated resistors
- Amber 7440/7443 turn signal LEDs
- White CANbus 7440/7443 LEDs (reverse/DRL)
- Switchback 7443 white/amber LEDs
- High-lumen 7440 reverse LED kits
- Parking / DRL LED variants
Because LEDs draw less current than halogen bulbs, some vehicles detect them as failed bulbs, causing hyperflash or dashboard warnings. Many bulbs in this collection integrate CANbus resistors or load circuitry to mimic halogen current and maintain the correct blink rate.
Housing compatibility includes reflector or lens-filtered rear lamp assemblies, where LED emitters must provide 360° beam fill to match filament distribution. In colored lenses, white LEDs rely on lens filtering, while clear lenses require amber or red LEDs to maintain DOT/ECE color compliance.
This category supports full rear lighting conversion through Underground Lighting, enabling brake, turn, tail, reverse, and DRL upgrades within the same bulb platform.
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