Buy Audi A4 Headlight Assembly

New Section:

Fast Facts

The Audi A4 headlight-also called a headlamp, front lamp, or light assembly-houses the bulbs, wiring, lenses, and control modules that let you see the road and be seen at night. It changes from one A4 generation to the next, but every version must aim light the right way, resist water, and meet safety laws. Upgrades now range from classic halogen bulbs to smart "matrix" LED systems that steer light around on-coming traffic. (Audi MediaCenter, Carifex)

New Section:

Fit Guide

• Model years & codes
  • B6 (2001-2005) and B7 (2005-2008) share similar housings; options were halogen H7 or xenon D1S/D2S projector units. (VAGLinks)
  • B8 (2009-2016) introduced LED daytime-running rings around the low-beam projector. (Jimdo)
  • B9 (2017-present) offers full LED or optional Matrix LED headlights that can blank out parts of the high-beam. (Audi MediaCenter)
• Common bulb bases (check owner's manual to confirm)
  • Low beam: H7 (halogen) or D3S/D1S (xenon HID) depending on trim. (ManualsLib)
  • High beam: H7 or an inner projector on HID cars.
  • Fuse/relay panels: under the dash and in the engine bay; diagrams vary by year. (StartMyCar, YouTube)

New Section:

Light Choices

← scroll table horizontally →

New Section:

Usual Troubles

• Condensation or fogging inside the lens often shows up after heavy rain; check the drain hole at the bottom of the housing and reseal the back-cap gasket. (Reddit, The Irish Sun)
• A "dipped-beam fault" warning that resets after a minute usually signals a weak HID ballast. (Audizine)
• Yellow or cloudy plastic comes from UV on the polycarbonate lens; polishing plus a UV-hard coat or clear film prevents repeat haze. (RadTech Journal, YouTube, Reddit)

New Section:

Care Tips

• Wash and dry the lens when you clean the windshield-dirt scatters light.
• Aim the beams against a flat wall 25 ft (7.6 m) away; both cut-off lines should sit at the same height and drop slightly to the right. (Connect NCDOT, YouTube)
• Pull the headlight fuse before bulb work to avoid shorts; fuse numbers vary by build year. (StartMyCar)

New Section:

DIY Install

1. Remove the top radiator cover and two T30 screws holding each lamp unit. (YouTube)
2. Slide the headlight forward, unplug the multi-pin connector, and lift out.
3. Swap the bulb or module-don't touch halogen glass with bare hands. (YouTube)
4. Refit, tighten screws to about 4 Nm, and test alignment.

New Section:

Rules & Safety

• U.S. law says low- and high-beam must come from separate light sources, which is why some Matrix functions are disabled here. (WIRED, NHTSA)
• Recall 941L (2024) updated A4 headlamp software so parking lights stay lit during a turn signal. (NHTSA)
• Many states check for moisture or bad aim during inspection; a foggy lamp can cause a test failure. (The Irish Sun)

New Section:

Upgrade Ideas

• Projector retrofit kits add clear lenses for a sharper cutoff on older B6/B7 housings.
• LED conversion bulbs cut power draw but must keep the beam pattern; look for ECE or DOT markings. (FORVIA HELLA)
• Paint-protection film (PPF) over the lens blocks UV and road chips. (YouTube)

New Section:

Q: Which years of A4 share the same headlight assembly?
A: B6 and B7 lamps interchange with minor wiring tweaks, but B8 and B9 units are different shapes and mounts. (VAGLinks, VAGLinks)

Q: How do I know if my A4 uses xenon or halogen bulbs?
A: Xenon cars have a silver ballast box under the lamp and auto-leveling motors; halogen units do not. (Audizine)

Q: Can I put LED bulbs in a halogen reflector?
A: Only if the LED bulb is marked road-legal and produces the same beam focus; otherwise it may cause glare. (FORVIA HELLA)

Q: What is Matrix LED?
A: It is an array of tiny LEDs that switch on and off to keep high-beam brightness while shading other drivers. (Audi MediaCenter, Carifex)

Q: Why do my lights flicker after start-up?
A: A weak ballast or low battery voltage can cause HID flicker; test voltage before replacing parts. (Audizine)

Q: Is moisture inside the lens normal?
A: A small mist that clears in minutes is normal; standing water or heavy fog needs resealing or vent cleaning. (Reddit, The Irish Sun)

Q: How often should bulbs be replaced in pairs?
A: Replace both sides at the same time; lamps dim with age so matching brightness keeps an even beam. (FORVIA HELLA)

Q: Do I need to disconnect the battery before changing bulbs?
A: Pulling the headlight fuse or turning off the lights is usually enough, but disconnecting the battery adds safety. (StartMyCar)

Q: What torque for headlight screws?
A: Factory spec is about 4 Nm (35 in-lb) for the upper T30 screws on B8/B9 cars. (YouTube)

Q: Will yellow lenses fail inspection?
A: Yes-cloudy plastic can cut output below legal limits; polishing and UV coating restores clarity. (RadTech Journal)

Q: Can Matrix high-beam be fully enabled in the U.S.?
A: Current federal rules prevent full adaptive high-beam; only partial functions run here. (WIRED)

Q: What does "dipped beam" mean?
A: It is the low-beam setting for normal night driving; in the A4, the dash warning tells you if the bulb or ballast fails. (Audizine)

Q: How do I aim my headlights at home?
A: Park 25 ft from a wall, mark center lines, and turn the vertical adjuster until the cutoff sits just below the height of the lamp. (Connect NCDOT, YouTube)

Q: Are aftermarket projector lenses legal?
A: Yes if they carry DOT/ECE marks and are aimed correctly; mis-aimed lights can be ticketed. (NHTSA)

Q: Do I need any coding after replacing a B9 headlamp?
A: Cars with matrix lights need a control-module adaptation with scan-tool software after replacement. (NHTSA)

Q: What is the easiest way to clear light fog?
A: Warm the lens gently with a hair dryer and open the rear cap to vent moisture. (The Irish Sun, Reddit)

Q: Are laser headlights used on the A4?
A: No, laser high-beam is available on some Audi sport models, not on the A4 line. (Dubizzle)

Q: Can I reuse HID bulbs?
A: Yes, but replace if the arc tube looks white or output has dropped-HID output fades over time. (FORVIA HELLA)

Q: What size fuse protects the headlight circuit?
A: Most A4s use a 15-amp mini-blade fuse; always verify in your year's diagram. (StartMyCar)

Q: Do foggy lights affect auto-leveling?
A: Moisture can corrode the leveling motor; fix leaks early to keep the motor working. (Audizine)

Q: Is extra sealant safe around the lens?
A: Yes-use butyl headlamp sealant rated for 120 °C so the joint stays flexible. (Reddit)

This guide should help you choose, fix, and upgrade any Audi A4 headlight while keeping your car safe and legal on every night drive.