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9004 Headlight Bulbs & Conversion Kits

Upgrade compatible 9004/HB1 headlights with LED bulbs, HID conversion kits, and replacement HID capsules designed for dual high/low beam systems. Choose the right lighting solution based on your vehicle's fitment and existing headlight setup.

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With a 4.95 average rating across Google and Judge.me, Underground Lighting has earned the trust of drivers looking for dependable LED lighting upgrades. See why customers choose us for fitment support, quality products, fast shipping, and brighter lighting solutions for cars, trucks, and SUVs.

Dual Beam 9004 Headlight Replacement Bulbs & Conversion Kits

The 9004 headlight bulb, also known by its ANSI designation HB1, is a dual-beam automotive lighting standard engineered to deliver both low beam and high beam output from a single bulb. It operates on a 12V DC electrical system, uses a P29t right-angle plastic base with three flat pins, and is commonly installed in 1990s–early-2000s cars, trucks, and SUVs with combined headlamp housings.

Unlike modern single-beam systems, the 9004 design integrates two filaments or dual light sources within one capsule. The low beam circuit runs at approximately 45W, while the high beam circuit operates at approximately 65W, allowing drivers to switch beam modes without separate bulbs or sockets.

This category includes OEM-fit 9004 HID replacement bulbs, 9004 HID conversion kits, and 9004 LED headlight upgrades designed around the optical geometry, electrical requirements, and connector layout of 9004 headlamp systems.

9004 / HB1 Bulb Technical Profile

  • Voltage: 12V DC
  • Wattage: 45W low beam / 65W high beam
  • Current Draw: ~3.75A low / ~5.4A high
  • Halogen Lumen Output: ~700–1,000 lumens low / ~1,200–1,500 lumens high
  • Standard Color Temperature: ~3200K warm white

These specifications make the 9004 a common candidate for LED or HID upgrades while retaining the original dual-beam format.

9004 vs 9007 vs H4 – Critical Fitment Differences

Choosing the correct bulb number is essential because similar-looking dual-beam bulbs are not automatically interchangeable.

3 Common Comparison Errors

  1. 9004 vs 9007: The base shape may appear similar, but the pinout and filament geometry differ. They are not interchangeable without the appropriate application-specific solution.
  2. 9004 vs H4: A 9004 uses a plastic right-angle base, while H4 uses a metal 3-tab base. Their physical connections are different.
  3. 9004 LED vs HID: LED provides instant illumination, while HID requires warm-up and ballast support.

Incorrect bulb substitution can result in poor fitment, incorrect beam positioning, glare, beam scatter, or an unsuccessful installation.

9004 HID Headlight Kits – High-Intensity Dual-Beam Upgrade

A 9004 HID headlight kit replaces the halogen low-beam filament with a xenon gas-discharge capsule powered by a 35W electronic ballast. In the high-end configuration, the low beam operates as HID while the high beam retains a halogen filament for faster beam switching.

  • Power: 35W HID low beam
  • Output: ~3700 lumens
  • High Beam: Halogen
  • Color Options: 3000K yellow, 6000K white, 8000K white/blue, 10000K blue

9004 HID Replacement Bulbs – Xenon Capsule Only

9004 HID replacement bulbs are designed for vehicles that already have a compatible 9004 HID conversion system. These bulbs do not include ballasts and rely on an existing 35W HID power source.

  • Lumen Output: ~3700 lumens
  • Technology: Xenon arc discharge
  • Color Temperatures: 3000K–10000K
  • Use Case: Replacement only, not a standalone upgrade

9004 LED Headlight Bulbs – Plug-and-Play Solid-State Option

A 9004 LED headlight bulb uses dual LED emitters to replicate high- and low-beam functions in a single housing. Light is generated via electroluminescence, eliminating filaments and reducing vibration-related failures.

  • Power: 60W system output
  • Brightness: ~7000 lumens per pair
  • Color Temperature: 6000K white
  • Installation: Plug-and-play P29t base

LED upgrades significantly reduce thermal load compared to halogen and provide instant full brightness, but correct emitter positioning remains important for maintaining proper beam control in reflector housings.

Choose from 9004 HID headlight kits, 9004 LED headlight bulbs, or xenon replacement capsules based on your existing system and the type of upgrade you need.

Why Choose Underground Lighting 9004 LED & HID Headlight Upgrades?

  • Dual-Beam High & Low Beam in One Bulb

    The 9004/HB1 format combines a 45W low beam and 65W high beam in one bulb position. Underground Lighting’s LED upgrade retains both beam functions, while the 35W Hi/Low HID kit uses HID for the low beam and halogen for an instant-response high beam.

  • 3–5× Higher Usable Light Output

    Underground Lighting offers significantly higher rated output options for compatible 9004 systems. The collection lists standard halogen output at roughly 700–1000 lumens low beam and 1200–1500 lumens high beam, compared with approximately 3700 lumens for HID and a 7000-lumen 9004 LED kit.

  • Faster Light Response vs Halogen

    Underground Lighting 9004 LEDs reach full brightness immediately when switched on. HID requires a short warm-up period, so the current Hi/Low HID kit retains a halogen high beam for immediate response while using 35W xenon HID for the low beam.

  • Reduced Replacement Frequency by 10–20×

    LED and HID technologies avoid the conventional dual-filament design used in 9004 halogen bulbs, helping reduce replacement frequency. As an OEM reference, OSRAM lists a standard 9004/HB1 halogen lamp at a 320-hour Tc lifespan, while solid-state LEDs can provide substantially longer operating life when properly cooled and driven.

  • Expanded Color Temperature Options for Specific Use Cases

    Underground Lighting’s 9004 HID options range from 3000K yellow through 6000K white to 8000K and 10000K blue-toned choices, while the current LED kit uses 6000K white. This gives drivers multiple beam-color choices without changing the 9004/HB1 bulb format.

  • Wide & Precise Visibility

    Correct emitter position matters in a dual-beam reflector housing. Underground Lighting’s 9004 LED kit uses an adjustable socket base, allowing the LED position to be aligned within compatible housings to support cleaner high/low beam distribution and reduce poorly placed hotspots or glare.

How to Choose the Right 9004 Headlight Bulb or Kit

Confirm your vehicle uses a 9004 / HB1 dual-beam bulb, then choose the option that matches your existing lighting system and housing.

  • Check fitment: Verify 9004 / HB1 using the original bulb or Vehicle Part Search.
  • Confirm dual-beam operation: The replacement must support both low and high beams.
  • Choose LED or HID: LED provides instant output, while HID requires the correct conversion setup.
  • Match your HID system: Use replacement HID bulbs only with an existing compatible HID setup; otherwise choose a complete kit.
  • Select the color temperature: Match the Kelvin option to your preferred light appearance.
  • Check beam compatibility: Correct bulb positioning helps maintain proper light distribution and reduce glare.
  • Verify before ordering: Use the Vehicle Part Search if fitment is uncertain.

Watch these helpful Underground Lighting videos for step-by-step guidance, product details, and real-world installation tips.

Find the Right 9004 Headlight Upgrade for Your Vehicle.

Vehicle Part Search

Call us at (561) 918-5225 or Send an Email

9004 Headlight Bulb FAQs

A 9004 / HB1 is a dual-beam headlight bulb that provides both high- and low-beam functions from a single bulb position. It uses a three-pin automotive connector and is commonly used in older cars, trucks, and SUVs.

The cost depends on whether you choose LED or HID technology. 9004 LED headlight bulbs are priced at $199.99 per pair. 9004 35W Hi/Low HID conversion kit costs $119.99 per pair and includes the bulbs and ballasts needed for installation. 9004 HID replacement bulbs are available for $49.99 per pair.

Yes. 9004 and HB1 are two names for the same dual-beam function in a single bulb. Always confirm the vehicle’s factory bulb specification before purchasing.

No. Although 9004 and 9007 bulbs look similar, their electrical pinouts and light-source geometry differ. Installing the wrong bulb can cause fitment problems or an incorrect beam pattern.

No. Both are dual-beam bulbs, but they use different bases and connector designs. A 9004/HB1 bulb should not be substituted with an H4 unless the headlight system has been specifically modified for that configuration.

Choose LED if you want instant full brightness, solid-state construction, and a relatively simple upgrade. Choose HID if you prefer xenon discharge lighting and your installation supports the required ballast and wiring. The better choice depends on the headlight housing, electrical system, and desired output.

Yes. HID bulbs require a ballast to regulate the voltage and current needed to ignite and operate the xenon arc. Replacement HID bulbs will not work correctly as standalone replacements in a standard halogen circuit.

Yes. You can install 9004 LED bulbs yourself if your vehicle already uses 9004/HB1 bulbs.  Before installation, check that the bulb fits your headlight housing and there is enough space for the LED bulb's heat sink, fan, or driver. You should also check the bulb's orientation and make sure the connection is secure. 

Yes, 9004 LED or HID upgrades can sometimes flicker. This happens because LED bulbs use less power than halogen bulbs, and the new lighting system is not fully compatible with the vehicle's electrical system. 

6000K is a popular choice for most drivers because it improves nighttime visibility, while 4300K to 5000K works better for fog, rain, or snow. Higher Kelvin values produce a bluer appearance but do not necessarily improve usable road illumination.

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