Audi A3 Fog Lights: Specs, Fitment & Common Faults

A genuinely alarming finding: multiple lights failing together was traced to a genuinely bad fuse box with several melted fuses inside — plus a confirmed Technical Service Bulletin for bi-xenon headlight flickering, and a clarification about shared fuses.

Illustration for editorial purposes

OEM Part Numbers

Accuracy note: we weren't able to verify a confident Audi A3 fog lights part number at the time of writing. Please confirm the correct part via an Audi dealer or parts specialist using your VIN.

Rarely Used, Easy to Forget About Until Needed

Fog lights sit unused for most owners most of the year, which means a fault can go unnoticed for a long time — right up until a genuinely foggy morning makes the problem obvious at the worst possible moment.

Before you buy: fog light fitment and bulb type vary by trim — not every trim level includes them as standard. Always confirm against your VIN before ordering.

What It Does

Front fog lights are angled and positioned to illuminate the road surface in low visibility conditions without creating the glare a standard headlight beam would in fog. Some higher trims of the A3 integrate fog lights into the same housing as cornering lights or daytime running lights, which affects both the part number and the complexity of any repair.

Fitment & Compatibility

Not every trim level of the A3 comes with fog lights fitted as standard, and the housing design often differs between trims that have them integrated with other lighting functions and those with a standalone unit. Always confirm your specific trim's fitment before ordering. Whether you're sourcing a replacement fog lights for your Audi A3 from a dealer, specialist, or online marketplace, always check compatibility against your registration or VIN before buying, and confirm you're ordering the correct side — driver's side (RH in the UK) or passenger side (LH in the UK) — since these are not interchangeable.

Common Faults

What to Look For

One side not working — usually a blown bulb, the most common and easiest fault to fix.
Neither side working — more likely a blown fuse or a faulty switch than two bulbs failing simultaneously.
Condensation inside the lens — points to a failed seal, worth addressing before it affects the bulb or wiring.
Cracked housing from front-end impact — common given their low mounting position, usually a straightforward like-for-like replacement.

DIY Replacement Difficulty

Bulb replacement is usually an easy DIY job, though access varies — some versions require reaching up from underneath via the wheel arch liner, others come apart from the front. Full housing replacement is similarly straightforward on most versions. Expect 15–30 minutes for a bulb swap, longer if the housing itself needs replacing.

A Genuinely Alarming, Real Finding Worth Knowing

If multiple lights fail together, such as a fog light indicator, headlight, and tail light all going out around the same time, this is genuinely worth knowing: one documented case traced exactly this pattern to a genuinely faulty fuse box, with several individual fuses found to be melted inside it. It's worth having the fuse box itself inspected if several seemingly unrelated lights fail together, rather than assuming several separate, coincidental faults. It's also genuinely worth knowing a confirmed technical service bulletin exists covering certain A3, A4, and TT models fitted with bi-xenon headlights, describing two related conditions: one xenon light sporadically flickering before going out, or one failing permanently — worth checking whether this bulletin applies to your specific car and headlight type if you're facing this exact symptom.

A genuinely useful clarification worth knowing about shared fuses: reverse lights, rear fog lights, and the number plate light can share a single, common fuse on some models — worth checking this specific fuse first if several of these fail together, rather than assuming three separate, unrelated faults.

It's also genuinely worth knowing an honest, useful finding: a complete lack of power to the front fog lights has, in at least one documented case, simply been down to dirty contacts or a relay that wasn't fully seated in its socket, rather than any genuine component failure — worth cleaning the relevant contacts and reseating the relay firmly before assuming a more involved fault.

OEM vs. Aftermarket

Reputable aftermarket fog light units and bulbs are a reliable, cost-effective alternative to OEM parts for the vast majority of cases, since this is a relatively simple lighting component without the complexity of adaptive or LED headlight systems.

More Audi Fog Lights Guides

The same part, covered across other Audi models.