Ford Focus Mk3 Tail Lights: Specs, Fitment & Common Faults

Saloon and hatchback Focus models use genuinely different tail light assemblies — plus what Ford's own handbook says about condensation.

Generation covered: this guide is for the third-generation Focus, built 2011–2018 (commonly the 2014–2018 registered examples still in daily use). The newer Mk4 Focus (2018–) uses different part numbers throughout — check your V5C logbook or VIN if you're unsure which generation you have.

Illustration for editorial purposes

Ford's Own Handbook Confirms Some Condensation Is Normal — Here's the Real Distinction

Worth knowing before assuming a fault: Ford's owner handbook explicitly states that condensation in exterior front and rear lamps is normal, since the units include vents designed to accommodate everyday humidity changes. Light misting that appears after washing, in rain, or overnight, then clears within a few hours as the light warms up, is genuinely nothing to worry about. What actually indicates a real problem: a persistent pool of standing water at the bottom of the unit, moisture that doesn't clear after several hours in the sun, or condensation that worsens over time — this points to genuine water ingress from a failed seal, which is worth having inspected rather than dismissed.

A Genuine Fitment Distinction: Saloon and Hatchback Use Completely Different Assemblies — Ford Focus Mk3 Tail Lights

Worth knowing before ordering: the Focus's tail light setup genuinely differs by body style, not just by generation. The saloon version uses a four-piece system including separate boot-mounted inner lights, while the hatchback uses a larger, simpler two-piece assembly on the quarter panels — these aren't interchangeable between body styles, so always confirm which body style you actually have before ordering, particularly if buying based on a generic "Ford Focus" listing rather than one specific to saloon or hatchback.

A genuinely useful bulb-type detail: most standard Focus trims use a conventional dual-filament bulb (commonly a 3157-type) handling both the running light and brake light function from a single bulb — inexpensive and easy to replace yourself. Higher trims like Titanium, or special editions with LED accents, generally aren't individually serviceable at the bulb level; if an LED element fails on these trims, the entire assembly typically needs replacing rather than just a bulb.

More Wiring Behind There Than Most People Assume

A tail light unit typically bundles several functions into one housing — brake light, indicator, reversing light and rear fog light — which means a single electrical fault can affect more than one function at once, and a "faulty tail light" can mean several genuinely different things.

Before you buy: tail light design and bulb type vary by trim and facelift status. Always confirm against your VIN before ordering.

Ford Focus Mk3 Tail Lights reference plate

OEM Part Numbers

Accuracy note: tail light part numbers vary by body style and, on saloon versions, by position — confirm exactly which light you need before ordering, since a visually similar unit for the wrong position won't fit.

Hatchback/estate tail light (common reference range)	Ford OEM: BM5Z-13404-B, CM5Z-13404-B
Facelift models (2015–2018)	Ford OEM: F1EZ-13404-D/FB, F1EZ-13405-A/B/D/FB
Typical bulb type	3157, 3157K, or 3157-SCK for combined brake/tail/indicator function

Important if your Focus is a saloon variant: the outer tail light (mounted to the metal quarter panel) and the inner tail light (mounted to the boot lid) are two entirely different parts with different part numbers — they are not interchangeable, so confirm which one you need before ordering.

What It Does

Beyond basic rear visibility, tail light units on the Focus Mk3 typically integrate brake lights, indicators, reversing lights and rear fog lights into a single housing. Higher trims may use LED units with a distinct light signature, which are not interchangeable with standard halogen units even if the physical mounting looks similar.

Fitment & Compatibility

Tail light design changed between generations of the Focus Mk3, and facelifted versions within the same generation often use a revised light signature that isn't interchangeable with pre-facelift units. Always confirm the exact part for your specific model year before ordering. Whether you're sourcing a replacement tail lights for your Ford Focus Mk3 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, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Tail Lights Guide for diagnosing which circuit has failed, how easy this job is to DIY, and aftermarket advice.

More Ford Tail Lights

The same part, covered across other Ford models.

Ford Focus Mk3 Tail Lights: Specs, Fitment & Common Faults

Ford's Own Handbook Confirms Some Condensation Is Normal — Here's the Real Distinction

A Genuine Fitment Distinction: Saloon and Hatchback Use Completely Different Assemblies — Ford Focus Mk3 Tail Lights

OEM Part Numbers

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