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H3 LED Bulbs & HID Conversion Kits

Built around the H3 bulb format, this range includes compact 2000LM CSP fog bulbs, 40W 6000LM LED upgrades, 3700LM HID replacement bulbs, and 35W CANbus HID conversion kits for H3-equipped fog, auxiliary, and compatible headlight applications.
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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.

H3 Bulbs for Fog Lights, Auxiliary Lamps & Compact Housings

This Underground Lighting collection is built exclusively around the H3 bulb, a single-beam automotive lighting standard defined by its PK22s metal flange base and integrated wire-lead electrical connection.

Unlike plug-in spade or wedge bulbs, the H3 format uses a spring-clip retention system and connects directly to the vehicle harness, making it structurally different from plug-in bulbs such as H1, H7, or H11. This design makes H3 bulbs especially common in front fog lights, auxiliary fog lamps, rally lights, and compact bumper-mounted housings, where space constraints and flexible wiring are required.

All products in this category operate on 12V automotive electrical systems and are designed for reflector-based housings, where the beam pattern is controlled by the housing geometry rather than the bulb itself. Because the H3 bulb has no built-in cutoff shield or indexing, correct alignment is critical to avoid glare and ensure proper road illumination.

What This H3 Collection Includes

1. H3 HID Replacement Bulbs – ~3700 Lumens (Pair)

Xenon HID arc bulbs produce light through an electric arc in xenon gas and require a 35W ballast or another compatible HID ballast. Available options include 3000K yellow, 6000K white, 8000K white/blue, and 10000K blue for existing H3 HID systems.

2. H3 HID 35W CANbus Error & Flicker-Free Kits

Complete H3 HID conversion kits including xenon bulbs, electronic ballasts, igniters, and CANbus load circuitry. Ignition voltage reaches ≈23,000V, with sustained operation at ≈85V AC, preventing dashboard errors and flicker in modern vehicles.

3. H3 LED Headlight Bulbs – 40W, ~6000 Lumens (Pair)

High-output solid-state LED replacements generating light through electroluminescence at a semiconductor p-n junction, delivering ~6000 lumens per pair at 6000K daylight white.

4. H3 40W 6000LM LED Fog Light Kits

Plug-and-play LED kits optimized for fog and auxiliary lighting, combining high lumen output, active or passive thermal management, and compact housings suitable for bumper-mounted fog lights. 

5. H3 LED CSP Bulbs – ~2000 Lumens

Compact LED replacements using CSP (Chip-Scale Package) LEDs, designed for tight housings, controlled brightness, and fog-light use where excessive output increases backscatter. 

Across all variants, brightness levels range from ~1450–1580 lumens (halogen baseline) to ~3700 lumens (HID) and up to ~6000 lumens (LED), allowing precise selection based on visibility needs and are designed for reflector fog light housings, where the H3 format is most effective, and are commonly used as H3 fog light bulbs, H3 headlight bulbs in auxiliary housings, or aftermarket fog-light upgrades.

Compared to a halogen, this H3 bulb collection provides 2–4× higher brightness, improved energy efficiency, and longer service life. However, because the H3 platform depends heavily on housing optics and correct alignment, proper installation is essential to avoid excessive glare or misdirected light, particularly with high-output LED and HID variants. Click here for our complete installation guide.

Be sure to browse our fog lights, turn signal lights, reverse / brake lights and switchback options, and confirm the right fit with our bulb finder.

Why Choose Underground Lighting H3 LED & H3 HID Upgrades

  • Up to 4× Higher Brightness Than Halogen H3

    Underground Lighting offers H3 LED and HID upgrades with published outputs from 2000LM to 6000LM, compared with approximately 1450LM for a standard 12V 55W H3 halogen bulb.

  • Optimized for Fog & Auxiliary Lighting

    The H3 range is built around fog, auxiliary, and compatible headlight applications, with compact bulb formats suited to low-mounted housings where correct positioning and controlled beam output matter.

  • Multiple Color Temperatures for Weather & Style

    Underground Lighting's H3 HID options include 3000K yellow, 6000K white, 8000K white/blue, and 10000K blue, providing different appearance choices for compatible applications.

  • CANbus-Safe Operation With HID Kits

    The 35W H3 CANbus HID kit pairs xenon bulbs with CANbus ballasts designed to help prevent flicker and bulb-out warnings on compatible vehicle lighting circuits.

  • Compact Form Factor for Tight Housings

    The H3 PK22s format suits compact lamp housings, while Underground Lighting also identifies when higher-output LED assemblies require additional rear clearance compared with a factory halogen bulb.

  • Improved Efficiency Over Halogen

    Underground Lighting's 40W LED H3 options use lower nominal wattage than a standard 55W H3 halogen while delivering higher published output, with dedicated thermal management controlling LED heat.

How to Choose the Right H3 Bulb

Start with your vehicle's H3 fitment, existing lighting technology, and available housing space before comparing output.

  • Confirm H3 fitment: Verify the bulb position by vehicle year, make, and model rather than assuming every fog or auxiliary lamp uses H3.
  • Existing HID system: Choose replacement HID bulbs when compatible ballasts are already installed; converting from halogen to HID requires a complete HID kit.
  • Fog or DRL use: The 18W CSP H3 LED is specifically listed for fog-light and daytime-running-light applications.
  • Higher-output LED: The 40W 6000LM LED options provide greater published output but require enough clearance behind the lamp housing.
  • CANbus monitoring: Use a compatible CANbus solution when the vehicle monitors the lighting circuit and produces flicker or bulb-out warnings.
  • Check alignment: Recheck beam position after an LED or HID upgrade, especially in reflector housings.

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

Find the Right H3 Fit for Your Vehicle

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

H3 LED Fog Lights FAQs

H3 lighting options currently range from $39.99 for HID replacement bulbs to $199.99 for the 35W CANbus HID conversion kit, with LED options priced between those points. Pricing can vary by product, color option, and promotion.

Repeated bulb failure can result from excessive voltage, poor electrical connections, vibration, heat buildup, moisture inside the housing, or contamination during installation. Check the socket, wiring, charging voltage, and housing condition before replacing the bulb repeatedly.

Yes. Underground Lighting's H3 HID replacement bulbs are listed as compatible with 35W and 55W HID ballasts. The bulb, ballast, and wiring must still be compatible with each other and with the vehicle application.

HID bulbs can shift in color as they age. A mismatch can also happen when bulbs have different Kelvin ratings, different operating hours, or one bulb or ballast is beginning to deteriorate. Replacing HID bulbs in pairs usually gives the most consistent color.

Check the bulb connection, ballast connection, ground, and power supply first. Swapping the left and right bulbs or ballasts can help identify whether the fault follows the bulb, ballast, or vehicle wiring.

Make sure the connector is completely in place and that power and ground are getting to the bulb. Some LED setups can also have issues with the way the wires are connected or with the car's monitoring systems, so you should check the wiring and CAN bus rules before thinking the bulb is broken.

Yes. Persistent condensation can corrode connectors, affect electrical contacts, and shorten component life. Check the bulb seating, gasket, rear cover and housing seals if moisture appears after installation.

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