Checking your car lights and indicators is one of the quickest pre-drive checks you can do — and one of the most important. A failed brake light means following drivers do not know you are stopping. A broken indicator means other road users cannot anticipate your next move. Both are legal offences, both are safety risks, and both can cause your RSA driving test to be refused before it even starts.

Source & Credit: Based on RSA Rules of the Road (Section 4: Vehicle Safety — Lights and Reflectors) and RSA driving test technical check requirements. Official resources at rsa.ie. BP Driving School is an RSA-approved ADI in Swords, North Dublin.
Vehicle Safety & Pre-Drive Checks — Article Series
In This Guide
  1. Why Lights and Indicators Matter
  2. Which Lights Are Legally Required?
  3. Car Lights — Front and Rear Overview
  4. The 12-Step Light Check Routine
  5. How to Check Brake Lights on Your Own
  6. Fog Light Rules in Ireland
  7. Dashboard Warning Signs for Lights
  8. Common Problems to Watch For
  9. Lights Check Before the RSA Driving Test
  10. Frequently Asked Questions

Why Lights and Indicators Matter

Your lights serve two distinct functions. Some help you see — headlights illuminate the road ahead in darkness. Others help others see you — tail lights, brake lights, sidelights and indicators communicate your position and intentions to every other road user around you.

A broken brake light means the driver behind has no warning you are slowing down. A failed indicator means other drivers and cyclists cannot anticipate your turn. A dim tail light makes you less visible to following traffic at night. None of these are minor issues — each is a direct safety risk and a legal offence.

RSA Rules of the Road: "It is an offence to drive an unsafe vehicle on a public road." A vehicle with required lights not working is not roadworthy. Driving with a failed brake light or indicator can result in a Garda stop and a requirement to repair the fault immediately.

Which Lights Are Legally Required?

The RSA Rules of the Road specifies the exact lights every motor vehicle must have:

PositionRequired LightsColour
FrontTwo headlightsWhite or yellow
Two sidelightsWhite
Direction indicator lightsAmber only
RearTwo tail lightsRed
Two brake lightsRed
Two reflectorsRed
Number plate lightingWhite (illuminates plate)
Direction indicator lightsAmber only
Fog lights are optional — not all cars are fitted with them. If your car has fog lights, they must only be used in dense fog or falling snow. Using them in clear conditions is prohibited. Rear fog lights are particularly powerful and can dazzle following drivers when used inappropriately.

Car Lights — Front and Rear Overview

Required Car Lights — Front and Rear (RSA specification)
Car lights diagram showing all legally required lights front and rear FRONT VIEW Head- lights Side- lights Indicator (amber) REAR VIEW NUMBER PLATE Tail & Brake Indicator (amber) Plate light + Reflectors
Front: headlights (white/yellow), sidelights (white), indicators (amber). Rear: tail lights (red), brake lights (red), indicators (amber), reflectors (red), number plate light (white). All are legal requirements on every Irish motor vehicle.

The 12-Step Light Check Routine

Work through this routine in order — it takes less than five minutes and covers every required light on the vehicle.

1Park safely on level ground

Find a flat, well-lit area where you can safely walk around the entire vehicle. Turn the engine off and apply the handbrake.

2Turn on sidelights — check front and rear

Switch on the sidelights (position lights). Walk to the front — both white sidelights should be on. Walk to the rear — both red tail lights should be on. Check for any obvious dimness or off-colour light suggesting a failing bulb.

3Check dipped headlights

Switch to dipped headlights. Stand in front of the car — both beams should be equally bright and aimed at the road, not the sky. Uneven brightness or a noticeably different beam shape means a bulb needs replacing.

4Check main beam (full beam)

Switch to main beam. Both beams should illuminate more of the road ahead at a higher angle. Check both sides are working equally.

5Check front left indicator

Activate the left indicator. Walk to the front left — the amber indicator should be flashing at a steady rate (around 60–120 flashes per minute). A very fast flash rate means a bulb is failing on that circuit.

6Check rear left indicator

Without cancelling the indicator, walk to the rear left and confirm the rear amber indicator is also flashing. Both front and rear must flash simultaneously on the same side.

7Repeat for right indicators

Cancel the left indicator, activate the right. Check both front right and rear right amber indicators are flashing correctly at a steady rate.

8Check hazard warning lights

Press the hazard button (red triangle symbol). All four indicators — front left, front right, rear left, rear right — should flash together simultaneously. Walk around the car to confirm all four are working.

9Check brake lights

See the dedicated section below — brake lights require a specific method to check without a helper. Both rear brake lights must illuminate when the pedal is pressed.

10Check reverse lights

Engage reverse gear with the handbrake firmly applied and the car stationary. Both rear reverse lights (white) should illuminate. Have a helper confirm this from behind, or use a reflective surface. Never stand behind a moving vehicle.

11Check fog lights (if fitted)

If your car has front and/or rear fog lights, activate them and confirm they illuminate. Note their position on the dashboard so you know how to operate them during the RSA technical check.

12Check number plate light and do a final walk-around

The number plate must be illuminated at night. Confirm the plate light is working with sidelights on. Then do one full circuit of the car, checking for cracked or cloudy light covers, uneven brightness, or any light that appears to be failing.

Pre-drive checks practised in your first EDT lesson

BP Driving School covers lights, indicators and all technical checks — RSA-approved, North Dublin, 7 days a week.

How to Check Brake Lights on Your Own

Brake lights are the hardest to check without help — pressing the pedal requires you to be in the driver's seat while the lights are at the rear. Here are three practical methods:

Checking Brake Lights — Three Methods
Three methods to check brake lights alone — reflective surface, helper, dashboard warning Method 1 Reverse up to a wall, garage door or shop window. 🧱 Brake lights reflect back — visible from seat Method 2 Ask a helper to stand safely to the side of the rear. 👤 Press brake — they confirm both lights illuminate Method 3 Modern cars with bulb failure sensors show dashboard warning. 🚗 Check instrument cluster for bulb warning light
Method 1 (reflective surface) works well in daylight. Method 2 (helper) is the most reliable. Method 3 (dashboard warning) only applies to newer cars with bulb sensors and should not be solely relied upon.
Never stand directly behind a stationary car with the engine running while checking lights. Even with the handbrake on, a vehicle can move. Have a helper stand to the side of the vehicle, not directly behind it.

Fog Light Rules in Ireland

The RSA Rules of the Road is clear on fog lights:

"You must only use fog lights in dense fog or falling snow. Turn them off in clear weather or you will risk causing glare and may dazzle other drivers."

This applies to both front and rear fog lights. Rear fog lights in particular are extremely bright — they can dazzle following drivers in clear conditions and reduce their ability to see your brake lights. Using rear fog lights inappropriately is a driving test fault.

If your car has fog lights, make sure you know:

  • Which switch operates the front fog lights (if fitted) and which operates the rear fog lights — they are often separate
  • What symbol appears on the dashboard when each is active (a lamp symbol pointing left for front fog, right for rear fog)
  • How to turn them off — so you can demonstrate this during the RSA technical check

Dashboard Warning Signs for Lights

Your dashboard provides clues about lighting faults. Common indicators to know:

  • Indicator arrow flashing on dashboard — should flash in sync with the indicator. Flashing unusually fast = a bulb on that side has failed
  • Bulb failure warning light — many modern cars have this; it illuminates when any external bulb is detected as failed
  • Rear fog light symbol (orange, pointing right) — confirms rear fog is active. Should only be on in fog or snow
  • Front fog light symbol (green, pointing left) — confirms front fogs are active
  • Main beam indicator (blue, headlights-style symbol) — confirms full beam is on
RSA test tip: the examiner will ask you to operate secondary controls including the lights. Know your car's specific symbols and switch positions before test day. Hesitation or operating the wrong control is a fault — practise in your test car beforehand.

Common Problems to Watch For

One bulb completely out

The most obvious fault — usually means the bulb has simply blown and needs replacing. Most bulbs are inexpensive and can be replaced at a garage or motor factor. Some modern cars require dealer replacement due to sealed units.

Indicator hyperflashing (flashing faster than normal)

A flash rate noticeably faster than usual on one side almost always means one indicator bulb on that circuit has failed. The circuit detects reduced resistance (one bulb instead of two) and increases flash speed. Check both front and rear indicators on the affected side.

Cracked or cloudy light covers

Physical damage to light covers can reduce light output and change the beam pattern. Cracked covers may also allow water ingress which damages the bulb holder. Have damaged covers replaced even if the bulb still works.

One side noticeably dimmer than the other

A bulb nearing the end of its life may dim before failing completely. If one headlight or tail light looks significantly dimmer than its pair, replace it before it fails entirely — do not wait for it to stop working.

Ignoring a dashboard bulb warning light

Many drivers dismiss dashboard warning lights. A bulb warning should be investigated immediately — it typically means a brake light, indicator, or other required light has failed and the car is technically unroadworthy until repaired.

Lights Check Before the RSA Driving Test

The RSA examiner checks lights and indicators as part of the technical checks at the very start of your driving test. They will ask you to operate lights and confirm they are working. A vehicle with required lights not functioning can result in the test being refused.

What to check the day before your test:
  • Both headlights (dipped and full beam)
  • Both front and rear indicators (left and right)
  • Both brake lights
  • Both tail lights and sidelights
  • Hazard warning lights (all four corners)
  • Reverse lights
  • Number plate light
  • Fog lights (if fitted)
Do not check lights the morning of the test — if you find a fault, you need time to fix it.
Preparing for your RSA driving test?

A mock test with BP Driving School covers all technical checks including lights — so the examiner's questions hold no surprises. North Dublin, 7 days a week.

Frequently Asked Questions

The RSA Rules of the Road requires: at the front — two headlights (white or yellow), two white sidelights, and amber direction indicators. At the rear — two red tail lights, two red brake lights, two red reflectors, number plate lighting, and amber direction indicators. All must be in working order at all times.

Check at minimum once a month, before any long journey, before your driving test, and any time you suspect a bulb may have failed. Get into the habit of a quick visual check each time you park at night — you can see whether tail lights are both on from the road behind as you lock the car.

Yes. The easiest solo method is to reverse the car close to a wall, garage door or shop window — the brake lights will reflect back and be visible as you press the pedal while seated. Alternatively, ask a helper to stand to the side of the rear (never directly behind) while you press the brake. Some modern cars also show a dashboard warning if a brake light bulb fails.

A faster-than-normal flash rate (called hyperflashing) almost always means one indicator bulb on that side has failed. The circuit detects reduced resistance from having one bulb instead of two, and the flash rate increases. Check both the front and rear indicator on the affected side and replace the failed bulb.

Yes. The RSA examiner performs technical checks at the start of the test including lights and indicators. If a required light is not working, the examiner can refuse to conduct the test on grounds the vehicle is not roadworthy. Always check all lights the day before your test — not the morning of.

Fog lights must only be used in dense fog or falling snow, as stated in the RSA Rules of the Road. Using rear fog lights in clear conditions is prohibited — they are extremely bright and can dazzle following drivers and obscure your brake light signals. Using fog lights inappropriately is a driving test fault.

Many modern cars have bulb failure sensors that illuminate a dashboard warning when an external bulb is detected as failed. If this appears, identify and replace the faulty bulb as soon as possible. A failed brake light or indicator is both a safety risk and a legal offence — do not ignore dashboard warnings.

Yes. The number plate light is a legal requirement — your registration must be visible at night. It is also checked during the RSA driving test technical checks. It is one of the most commonly overlooked lights in routine checks because it is small and easy to miss during a visual walk-around.
More from the Vehicle Safety & Pre-Drive Checks series
Lights are checked at the very start of your RSA driving test.
Your first EDT lesson with BP Driving School covers all secondary controls and lighting checks — exactly as the examiner requires. Book your EDT course — RSA-approved, Swords, North Dublin.

Nearly test-ready? Book a mock test and rehearse the full technical check sequence the examiner will run through on test day.