Hi Steve sorry it's a bit late. I copied this from the 2018 tester's manual.
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4.1.2 Headlamp alignment
You must inspect all dipped beam headlamps fitted.
The type of headlamp will determine whether the aim must be checked on dipped or main beam (see Diagrams 1, 2 and 3).
A flat top or other alternative headlamp dipped beam pattern is acceptable as long as all of the beam upper edge, including any ‘peak’ is contained within the appropriate tolerance band.
It's acceptable for masks or converter kits to be fitted to right hand dip headlamps to temporarily alter the lamp for use in the UK by removing the beam ‘kick-up’ to the right.
If driver’s beam aim controls are fitted, you should test the beam aim without altering the control setting. If this would result in failure for beam aim being too low, you should re-check the beam aim with the control set at its ‘highest’ position.
On vehicles with hydro-pneumatic suspension systems, it's necessary to have the engine running when checking headlamp aim.
To check the aim:
- Position the vehicle on the designated headlamp aim standing area.
- Align the headlamp aim testing equipment to the vehicle in accordance with the manufacturer’s instructions.
- Determine the appropriate headlamp beam image and its aim (see Diagrams 1, 2 and 3).
For complex lens systems – meaning those that have more than one lamp behind a single lens – make sure the test equipment is aligned exactly on the centre of the dipped beam pocket.
You mustn’t carry out repairs during an MOT test, but you can make minor adjustments to the headlamp aim.
European type – check on dipped beam
European type lamps have one of the following:
- an asymmetric dipped beam pattern with
- a horizontal cut-off on the right
- a wedge of light above the horizontal towards the left, known as the 'kick up'
- lens may have European approval mark
For European type lamp to pass, you must make sure that:
- beam image 'kick up' is visible on the screen
- for headlamps with centres at 850mm or less from the ground, the beam image horizontal cut-off is between the 0.5% and 2.75% horizontal lines
- for headlamps with centres more than 850mm from the ground, the beam image horizontal cut-off is between the 1.25% and 2.75% horizontal lines
- white light doesn't show in the zone formed by the 0% vertical and 0.5% horizontal line
Diagram 1. Aim information
British American headlamp – check on main beam
British American type headlamps are checked on main beam if they have an asymmetric main beam pattern with a central area of maximum intensity, known as a ‘hot spot’.
The generally also have a circular lens marked with a figure ‘1’ followed by an arrow indicating the direction of dip.
You must fail a British American type lamp if the 'hot spot' is:
- above the horizontal 0% line
- below the horizontal 2% line for headlamps with centres at 850mm or less from the ground
- below the horizontal 2.75% line for headlamps with centres more than 850mm from the ground
- to the right of the vertical 0% line
- to the left of the vertical 2% line
For a British American type lamp to pass, you must also make sure the brightest part of the image moves downwards when the lamp is dipped.
Diagram 2. Main beam image
British American headlamp – check on dipped beam
Check British American headlamps on dipped beam if they have:
- an asymmetric dipped beam pattern with a flat-topped area of high intensity extending above and parallel with the horizontal 0% line on the nearside
- a circular lens marked with the figure 2 – it might also have an arrow showing the direction of dip
You must fail this lamp if the 'hot spot':
- upper edge is above the horizontal 0% line
- upper edge is below the horizontal 2.75% line
- right-hand edge is to the right of the vertical 0% line
- right-hand edge is to the left of the vertical 2% line
Diagram 3. Dipped beam image
Defect Category
- The aim of a headlamp is not within limits laid down in the requirements
Major
- Headlamp aim unable to be tested
Major
Tony.
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