This proposal concerns lamps equipped with several light sources and fitted with an operating tell-tale that indicates the failure of any one of these light sources. The current provisions for the failure of one light source (the “N-1” requirement) are difficult to apply as a complete photometric check for all possible combinations of light source failure is required. The revised text follows the approach of supplement 17 to Regulation No. 87 and removes the requirement to check the complete photometric requirement, in case of failure of any light source, when the lamp is fitted on the vehicle with an operating tell-tale.
In paragraph 9, the opportunity has been taken to correct a reference to paragraph 3. of Annex 4. The reference should be to paragraph 4 of Annex 4.