Interpretation ID: nht71-4.9
DATE: 09/02/71
FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA
TO: Philadelphia Newspapers, Inc.
TITLE: FMVSS INTERPRETATION
TEXT: In your letter of August 18 you ask for a ruling on the permissibility of wiring one filement of a clearance lamp on your small delivery truck so that it would function as a stop lamp and turn signal lamp.
Federal Motor Vehicle Safety Standard Ho. 108, Lamps, Reflective(Illegible Words), does not prohibit combining a clearance lamp with a stop lamp or a turn signal lamp. However, the maximum allowable mounting height above the road surface for stop lamps is 72 inches measured from the center of the item with the vehicle at curb weight. There is currently no restriction on the maximum allowable mount(Illegible Words) however they may not be amounted higher than(Illegible Word) inches on vehicles manufactured on or after January 1, 1972. These restrictions, however, do not apply to supplemental lamps mounted higher than 72 or 88 inches, as long as a vehicle is equipped with stop lamps and turn signal lamps located within the mounting range prescribed by Standard No. 108,(Illegible Word) inches to 72 or 83 inches, as applicable, above the road surface.
The Federal motor vehicle safety standards do not apply to a vehicle "after the first purchase of it for purposes other than resale." If the alterations are to be made to vehicles already in the PHI fleet, the question of the legality of your modifications would be covered by regulations of the Bureau of Motor Carrier Safety, if your vehicles are subject to them, and by State and local laws.