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Combination Stop, Turn and Tail Lamps and Rear Clearance Lamps Alex Stowe, NATM Technical Director
The NATM Compliance Team has received some questions recently from members relating to rear clearance lamps and whether or not a clearance lamp may be combined with a stop, turn and tail lamp to the meet the lamp requirements under the Federal Motor Vehicle Safety Standard’s (FMVSS) lamp regulations.
Short Answer: This would not be compliant under the FMVSS lamp regulations. The FMVSS lamp regulations specifically prohibit clearance lamps from being optically combined with any tail lamp. (FMVSS 571.108) A clearance lamp may be combined with a side marker lamp, if the lamp is installed at a 45° angle it must meet the correct SAE lens coding requirements, PC or PC2 lenses must be used for clearance and side marker lamps installed at a 45° angle whereas P2 or P3 lenses may be used when the light is flush against the trailer/fender .
Long Answer: Clearance lamps are defined by the FMVSS as “lamps which show the front or rear of the vehicle, mounted on the permanent structure of the vehicle as near as practicable to the upper left and right extreme edges to indicate the overall width and height of the vehicle.” Tail lamps are defined as “steady burning low intensity lamps used to designate the rear of a vehicle.” 24
March/April 2022
FMVSS §571.108 S6.3.3 specifically mentions that “No clearance lamp is permitted to be optically combined with any tail lamp.” The FMVSS lamp regulation also mentions “Combination clearance and side marker lamps are single lamps which simultaneously fulfill the requirements of clearance and side marker lamps.” Because of this language, the NATM lamp standard used in our compliance verification program also does not allow for a clearance lamp to be used in combination with a stop, turn and tail lamp. As mentioned above, the regulations do allow for clearance lamps to be combined with some other lamps, assuming location and bulb requirements can be met for the combined lamps, but the regulation specifically states that clearance lamps cannot be combined with any tail lamp. When looking to combine a clearance lamp with another lamp on a trailer, it is important to remember that clearance lamps must have the correct SAE lens coding. This lens coding is normally located either directly printed on the lens itself, or in documentation provided by your supplier. Rear clearance lamps either need to have lens code P2 or P3 for standalone clearance lamps, or lens code PC or PC2 for rear clearance lamps installed at a 45° angle on the vehicle. The clearance lamps must be mounted at the widest point of the trailer and as high as practicable. ■ www.NATM.com
