Interpretation ID: aiam2451
Director of Engineering
Trailer Manufacturers Association
401 North Michigan Avenue
Chicago
IL
60611;
Dear Mr. Reed: This is in reply to your letter of October 29, 1976, asking whether th '47 Series Tite-Lite,' in our opinion, has an ''optically combined' clearance lamp function.' The lamp in question is represented as having 'two lights [that] provide 15 functions' and you have advised us that 'there are no partitions inside the multi-function lens of this lamp.'; Paragraph S4.4.1 of Motor Vehicle Safety Standard No. 108 prohibits th optical combination of clearance lamps with tail lamps and identification lamps. This means that a single bulb in the 47 Series Tite-Lite may not provide both tail lamp and clearance lamp functions. It also means that the light emitted by one bulb must not be perceived as performing the function of the other in addition to its design function. You have neither identified the function performed by both bulbs nor provided us with their candle-power output and we are unable to determine whether the lamp complies with Standard No. 108.; Sincerely, Frank A. Berndt, Acting Chief Counsel