All control questions / Lights

Control questions about lights

Dipped and main beam, indicators, brake lights and the other lights: what to check, and how.

1. How do you check that the dipped headlights work and are correctly adjusted?

   The beam must light the kerb side more than towards oncoming traffic, and you must be able to see at least 30 m ahead. It must be white or yellow.

   Dipped headlights are asymmetric, so they light up the kerb side without dazzling oncoming traffic. They must light the road at least 30 m ahead.

   How to show it on the car:

   1. Switch on the dipped headlights.
   2. Walk round to the front and check that both headlights are on.
   3. Show against a wall that the beam points down and mostly towards the kerb side.

2. How do you check that the rear lights work?

   They must be red.

   Rear lights must be red. White light to the rear is only allowed from the reversing light and the number plate light.

   How to show it on the car:

   1. Switch on the lights.
   2. Walk round to the back and check that both rear lights shine red.
   3. Check that the lenses are intact.

3. How do you check that the main beam (high beam) works?

   You must be able to see 100 m ahead. The light must be white or yellow.

   Main beam must light the road at least 100 m ahead. Remember to dip your lights when you meet other traffic or drive close behind someone.

   How to show it on the car:

   1. Switch on the lights and select main beam with the light stalk.
   2. Check that the blue main-beam light comes on on the dashboard.
   3. Check at the front that both lights shine brighter.

4. How do you check that the indicators work?

   I start the car, push the indicator stalk up and down and check that the indicators flash correctly, front and rear.

   Check both sides, front and rear. If one side flashes faster than normal, a bulb has often failed.

   How to show it on the car:

   1. Switch the ignition on.
   2. Push the indicator stalk up for right and down for left.
   3. Walk around the car and check the indicators at the front, rear and sides.

5. How do you check that the hazard warning lights work?

   I press the red triangle button and check that all four indicators flash – front, rear and on both sides.

   The hazard lights switch on all indicators at once. They are used when the car is a danger to others, for example after an accident or a breakdown.

   How to show it on the car:

   1. Press the button with the red triangle.
   2. Check that all indicators flash together and that the button or warning light flashes too.

6. How do you check that the position lights work?

   Switch on the position lights and walk around the car. Check that the lights are on at both the front and rear.

   The position lights must work both front and rear so the car can be seen when it is parked in the dark.

   How to show it on the car:

   1. Turn the light switch to position lights.
   2. Walk around the car and check the small lights at the front and rear.

7. How do you check that the brake lights work?

   I press the brake and look for the reflection in a window, or ask a helper to watch from behind.

   Brake lights shine red and brighter than the rear lights when you brake. Ask someone to watch, or look for the reflection in a window or garage door.

   How to show it on the car:

   1. Ask a helper to press the brake, or watch the reflection in a window or garage door.
   2. Check that both brake lights – and the high brake light, if fitted – shine brighter.

8. How do you check that the number plate light works?

   I switch on the lights, walk to the back and check that the number plate is clearly lit by all lamps.

   The number plate must be lit so it can be read in the dark. If the car has several lamps, they must all work.

   How to show it on the car:

   1. Switch on the lights.
   2. Walk round to the back and check that the number plate is lit by all its lamps.

9. How do you check that the reversing light works?

   With the ignition on, I put the car in reverse and look behind the car or at a reflection to see if white light comes on.

   The reversing light shines white to the rear and shows others that you are reversing. It only comes on when reverse gear is selected.

   How to show it on the car:

   1. Switch the ignition on and press the clutch or brake.
   2. Select reverse gear.
   3. Check behind the car or in a reflection that the reversing light shines white.

10. Why must the light lenses be clean and intact?

    Dirt and cracks make the light weaker and scatter it, so I see less and may dazzle oncoming traffic.

    Dirty lights can give much less light and scatter it so oncoming drivers are dazzled. Keep all lights clean, especially in winter.

    How to show it on the car:

    1. Walk around the car and look at all the lights.
    2. Wipe off dirt, snow and ice, and look for cracks.

11. How do you check that the rear fog light works, and when may you use it?

    I switch it on and check at the back that it shines bright red. It may only be used when visibility is severely reduced.

    The rear fog light is very bright and dazzles the cars behind you if used in normal weather. Only use it in thick fog, heavy snow or similar, and switch it off when visibility improves.

    How to show it on the car:

    1. Switch on the dipped headlights, then the rear fog light.
    2. Point to the amber indicator light for the rear fog light.
    3. Check behind the car that the light shines bright red.

12. What do you use the headlight levelling control for?

    To lower the beam when the car is heavily loaded at the back, so oncoming traffic isn't dazzled.

    When the back is heavily loaded, the headlights point upwards and dazzle oncoming drivers. The levelling control – often a numbered wheel near the steering wheel – lowers the beam again.

    How to show it on the car:

    1. Find the headlight levelling wheel near the steering wheel or light switch.
    2. Explain that 0 is for an empty car and higher numbers lower the beam when loaded.

13. When must the car's lights be on?

    The lights must always be on while driving, even in daylight. The car may have automatic daytime running lights.

    In Denmark, lights must always be on while driving, day and night. Most new cars have daytime running lights (DRL) that come on automatically, but DRL don't always light the rear – check that the rear lights are on when it gets dark.

14. When may you use the front fog lights?

    Only when visibility is seriously reduced, e.g. in dense fog, heavy rain or snowfall.

    Front fog lights may only be used when visibility is seriously reduced. They may be used with dipped headlights or on their own. Remember to switch them off when conditions improve, as they can dazzle other road users.

    How to show it on the car:

    1. Show where the front fog light switch is.
    2. Switch them on and walk round to the front to check that both are on.