This
inspection applies to: all obligatory headlamps, and optional (additional) dip
beam headlamps.
Type of headlamp
The aim of headlamps must be checked on main or dipped beam according to their
type. See diagrams 1, 2 or 3, which include details appropriate to each headlamp
type.
These methods of inspection involve the use of beam checking equipment with a
collecting lens.
Masks or converter kits
Right hand dip headlamps can be temporarily altered for use in the UK by
fitting masks or converter kits which remove the beam ‘kick-up’ to the right.
A headlamp altered in this way is not a reason for rejection, if
a. the headlamp aim is not rejected for the reasons listed under diagram 1 (except
that the top of the beam image will be a straight line)
b. the light output is not unduly reduced - not usually a problem with commercially
produced kits
c. the mask or converter is securely attached
Driver’s beam aim controls
Where these are fitted the beam aim should be tested without altering the control
setting except where this would result in failure for beam aim being too low.
In such cases the beam aim should be re-checked with the control set at its ‘highest’
position.
Testing headlamps with complex lens systems.
Complex headlamp systems are those that have more than one lamp behind a single
lens.
It is essential that the headlamp aim test equipment is aligned exactly on the
centre of the dipped beam pocket.
If when carrying out a normal test a clearly defined headlamp pattern cannot be
seen, it will be necessary to move the vehicle closer to the test equipment.
It is essential that the car headlamp and test equipment are as close together
as possible, otherwise the whole of the beam pattern may not be visible |
To check headlamp
aim
A1. Position the vehicle on the designated headlamp aim standing area.
Follow the headlamp tester manufacturer’s user manual instructions, and align
the headlamp aim equipment with the longitudinal axis of the vehicle.
Align the centre of the collecting lens with the centre of the headlamp under
test.
Switch on the headlamps to the beam on which the headlamp is to be checked.
Note: When checking headlamp aim on vehicles with hydro-pneumatic suspension systems,
it is necessary to have the engine idling.
Determine the appropriate headlamp beam image and its aim (See diagrams 1, 2 and
3). Older vehicles (approx. pre 1950) headlamps beam image may not conform to
either Diagrams 1, 2 or 3.
In such cases check
• dip beam headlamps are aimed so they do not dazzle, ie the beam image brightest
part is aimed at least 0.5% below the horizontal
or for headlamps which cannot be checked on dip beam, check
• main beam headlamps are aimed so that the beam image centre is on or slightly
below the horizontal.
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A1. An old (approx.
pre 1950) vehicle with a headlamp which does not conform to diagrams 1, 2 & 3
that has a beam image which is aimed so that it dazzles other road users.
An alternative headlamp dipped beam pattern (not being one of the examples) is
acceptable providing all of the beam upper edge, including any “peak” is contained
within the appropriate tolerance band.
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