Part IRequirements Relating to Obligatory Dim-Dip Devices and Running Lamps
1. A dim-dip device fitted to satisfy regulation 21 shall cause light to be emitted from the dipped-beam filament of each obligatory dipped-beam headlamp, each such light having, so far as is practicable, an intensity of between 10 and 20 per cent. of the intensity of the normal dipped beam.
2. Running lamps fitted to satisfy regulation 21 shall be in the form of a matched pair of front lamps each of which—
(a)is fitted in a position in which an obligatory front position lamp may lawfully be fitted, and
(b)is capable of emitting white light to the front having an intensity of not less than 200 candelas, measured from directly in front of the centre of the lamp in a direction parallel to the longitudinal axis of the vehicle, and of not more than 800 candelas in any direction.
3. The electrical connections to the obligatory dim-dip device shall be such that the light output specified in paragraph 1 is automatically emitted whenever the following four conditions are satisfied, namely—
(a)the engine is running, or the key or devices which control the starting or stopping of the engine are in the normal position for when the vehicle is being driven;
(b)the obligatory main beam and dipped beam headlamps are switched off;
(c)any front fog lamp fitted to the vehicle is switched off; and
(d)the obligatory front position lamps are switched on.
4. The electrical connections to the obligatory running lamps shall be such that the light output specified in paragraph 2 above is automatically emitted, whenever the conditions set out in sub-paragraphs (a), (b) and (c) of paragraph 3 are satisfied.