What is the low beam headlight bulb size for a 2004 Audi A4 Quattro?

The 2004 Audi A4 Quattro uses a H7 bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 2004 Audi A4 Quattro?

The high beam bulb size for the 2004 Audi A4 Quattro is H7.

Why are my 2004 Audi A4 Quattro headlights dim?

Dim headlights on a 2004 Audi A4 Quattro can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a H7 LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2004 Audi A4 Quattro fog light?

The 2004 Audi A4 Quattro uses a H11 bulb for the fog light position.

Is the 2004 Audi A4 Quattro single or dual beam?

The 2004 Audi A4 Quattro uses a single bulb (dual filament) headlight system. This means one bulb controls both high and low beams.

Can I install LED bulbs on my 2004 Audi A4 Quattro?

Yes, the 2004 Audi A4 Quattro comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a H7 LED conversion kit for the low beams.

Does the 2004 Audi A4 Quattro have fog lights?

Yes, the 2004 Audi A4 Quattro takes a H11 bulb for the fog light position.

Did the 2004 Audi A4 Quattro change headlight bulb sizes from the previous year?

Yes — the 2004 Audi A4 Quattro uses different bulb sizes than the 2003 model. The 2004 generation introduced this bulb configuration.

Is the 2004 Audi A4 Quattro the first or last year to use H7 bulbs?

The 2004 Audi A4 Quattro is the only year in the 2004 generation to use the H7 bulb for the low beam headlight.

How do I change the headlight on a 2004 Audi A4 Quattro?

Turn off the vehicle and open the hood. Locate the headlight assembly from behind, remove the dust cover or retaining clip, disconnect the wiring harness, twist the old H7 bulb counter-clockwise to remove it, then insert the new bulb and reassemble. Note: Audi vehicles use a CANbus system, so LED replacements may need an anti-flicker decoder. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 2004 Audi A4 Quattro?

LED bulbs used off-road or in auxiliary lights are legal everywhere. For on-road headlight use, legality varies by state. Many states allow LED retrofits as long as the beam pattern meets DOT standards. For the best legal compliance, choose a DOT-approved H7 LED kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 2004 Audi A4 Quattro headlights?

A pair of halogen H7 bulbs costs $15 to $40, while LED conversion kits run $25 to $60 per pair. If you have a shop do the work, expect an additional $20 to $50 in labor per bulb. Replacing them yourself at home saves the labor cost and usually takes under 30 minutes.

What is the difference between halogen and LED for a 2004 Audi A4 Quattro?

Halogen bulbs produce a warm yellow light (around 3200K), last 500 to 1000 hours, and draw more power. LED bulbs emit a brighter white light (5000-6000K), last 25,000+ hours, and use less energy. LED upgrades for the H7 position are available as direct plug-and-play replacements. Since the Audi uses CANbus monitoring, choose a CANbus-compatible LED kit to avoid dashboard errors.

The 2004 Audi A4 Quattro has a unique bulb configuration not shared with adjacent model years.

Fitment Guaranteed for 2004 Audi A4 Quattro

What Size Bulbs Does a 2004 Audi A4 Quattro Use?

Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.

Installation Difficulty

Hard (Tight clearances)

Est. Replacement Cost

$15 - $40 (Halogen) / $30+ (LED)

What Lighting System Does the 2004 Audi A4 Quattro Have?

Lighting on the 2004 Audi A4 Quattro is managed by a total of 10 bulbs, covering everything from primary headlights to signal indicators. It features a comprehensive lighting system powered by a halogen-based setup where a single H7 dual-filament bulb handles both low and high beam duties within the same reflector. Note that Audi vehicles typically feature a CANbus electrical monitor that checks for specific bulb resistance.

LED Flicker Warning

This vehicle is known to use a CANbus system. Installing standard LEDs may cause flickering.

Use a CANbus decoder.

Can You Put LED Bulbs in a 2004 Audi A4 Quattro?

Upgrading to LED is one of the most effective ways to modernize your Audi's appearance and safety profile. Since your A4 Quattro uses a single H7 bulb for both high and low beams, ensure your chosen LED kit is "dual-beam" compatible. This allows the LED circuitry to mimic the two-filament design of the original halogen bulb. Because Audi utilizes a CANbus system, standard LED bulbs may cause "bulb out" errors on your dashboard. Always opt for "Error-Free" or CANbus-ready kits which include the necessary resistors. Don't forget the H11 fog lights; switching these to LED can dramatically improve your visibility in adverse weather.

2004 Audi A4 Quattro Bulb Size Chart

Position	Bulb Size	Shop
Fog Light	H11	Buy H11 →
Side Marker	3457NA	Buy 3457NA →
High Beam	H7	Buy H7 →
Low Beam	H7	Buy H7 →
Brake Light	7528	Buy 7528 →
Tail Light	7225	Buy 7225 →
Turn Signal Rear	7507	Buy 7507 →
Parking Light	3457NA	Buy 3457NA →
Door Light	W5W	Buy W5W →
Trunk Light	W5W	Buy W5W →

How do the 2004 Audi A4 Quattro's bulbs compare to other years?

The 2004 Audi A4 Quattro changed bulb sizes from 2003. The previous model year used a different configuration.

The 2005 model switched to a different bulb configuration.

This bulb configuration covers the 2004 model years. ← 2003 2005 →

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Other A4 Quattro Years

2020 2019 2018 2017 2016 2015 2014 2013 2008 2007 2006 2005 2003 2002 2001 2000 1999 1998 1997 1996

Other Vehicles That Use H7 Bulbs

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H7 Comparisons

9005 vs H7 H1 vs H7 H11 vs H7 H4 vs H7