Clocks Go Back: Headlight and Bulb Checks Before the Dark Nights

You gain an hour in bed on the last Sunday of October, but you lose it on the road. When the clocks go back at 2am on 25 October 2026, sunset jumps an hour earlier, and the evening commute that was comfortable in daylight suddenly falls in the dark. From that week on, you are relying on your lights every single day.

That makes late October the natural moment to check that every bulb still works. One blown bulb is easy to miss — you rarely see your own tail lights — and it is one of the most common faults on the road. Here is a five-minute check worth doing before the dark nights arrive.

Do a full bulb walk-round

Do not just check the headlights and assume the rest are fine. Work through every light on the car, front and rear:

• Dipped and main beam — switch between the two and check both sides light up.
• Sidelights and tail lights — the small running lights, easy to overlook.
• Brake lights — press the pedal with someone watching, or reverse towards a wall and look at the reflection. Include the high-level third brake light.
• Indicators and hazards — front and rear, both sides, plus any side repeaters.
• Fog lights — front (if fitted) and rear.
• Number-plate light — a common blown bulb and an instant MOT failure.
• Reversing light — select reverse and check it comes on.

If you are on your own, park facing a wall, garage door, or shop window and use the reflection. It costs nothing and catches the one bulb you would never have spotted otherwise.

Clean cloudy or yellowed lenses

Headlight lenses are plastic, and over the years UV light oxidises them so they turn cloudy and yellow. It happens so gradually you stop noticing — but a hazed lens can cut light output dramatically, so you are driving on far less beam than you think.

• Check in daylight — look for a milky, yellow, or foggy surface rather than clear plastic.
• Restore or replace — a proper headlight restoration kit brings most lenses back for a few pounds and some elbow grease. Badly degraded units are cheap to replace.
• Do it before winter — clear lenses matter most in the exact conditions you are about to face nightly.

Check the aim and do not dazzle

Bright, working headlights are no good if they are pointing in the wrong place. Misaimed or overly bright headlights dazzle oncoming drivers and are dangerous for everyone.

• Check the beam height — if you have changed a bulb or carry heavy loads in the boot, the beam can tip upwards. Use your headlight levelling dial if the car has one.
• Dip for oncoming traffic — drop from main to dipped beam in good time for approaching cars and when following someone closely.
• Avoid illegal bulbs — over-bright aftermarket bulbs fitted to standard housings scatter glare and are not road-legal. Stick to the correct rating for your car.

Do not rely on daytime running lights

Modern cars fire up their daytime running lights automatically, which makes it easy to assume you are fully lit. You are not. DRLs usually light only the front of the car, leaving your tail lights dark — so drivers behind you cannot see you in gloom or heavy rain.

Switch your proper headlights on at dusk, in poor weather, and in fog. If the dashboard shows only the DRL symbol and not the headlight symbol, your rear lights are off.

Why it matters beyond safety

This is not only about seeing and being seen. Lighting and signalling faults are consistently the single most common category of MOT failure in the UK — so the same walk-round that keeps you safe on the dark commute also keeps you MOT-ready. We cover the full picture in our guide to the most common MOT failures.

If you are not sure when yours is due, run a free MOT check on your registration to see the current status and expiry date. If an autumn or winter MOT is coming up, set a free MOT reminder so it does not creep up on you in the dark half of the year.

Once the lights are sorted, the natural next step is the rest of the car — battery, tyres, screenwash, and coolant. Our guide to preparing your car for winter walks through it, and if a warning light appears, our dashboard warning lights guide explains each one.

The bottom line

The clocks going back is a useful annual prompt: from 25 October you are driving in the dark daily, so make sure every light works before you depend on it. Spend five minutes on a full bulb walk-round, clean any cloudy lenses, check your aim, and switch proper headlights on at dusk rather than trusting daytime running lights.

Run a free MOT check now to confirm your status, and set an MOT reminder if yours falls in the darker months ahead.