Interpretation ID: nht68-2.39

DATE: 09/20/68

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TO: White Trucks, Division of White Motor Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of May 22, 1963, to Mr. David A. Fay, concerning a clarification of the requirements of paragraph S3.4.3 of Motor Vehicle Safety Standard No. 108.

As a truck-tracter manufacturer, your responsibility with respect to the requirements of paragraph S3.4.3 may be set by installing on your truck-tractors the switches, wiring and trailer electrical connectors that will, when properly mated with the wiring and electrical plugs on the trailern that are designed to be used with your particular electrical circuitry, cause the trailer tail lamps and the truck-tractor tail lamps to be illuminated when the truck-tractor headlamps are illuminated. If your truck-tractors are subsequently used to tow trailers that are not equipped with properly mated electrical plugs, connectors or circuitry, then you are not burdened with the responsibility of providing, for the resulting tractor-trailer combination, electrical circuitry that will cause the trailer tail lamps to be illuminated then the tractor headlamps are illuminated.

The trailer electrical connector that is installed on the tractor may be the 7-wire connector conforming to SAE 3560a, a 6-wire connector, or a special connector as specified by your customers. In this respect, we agree that your cannot ascertain at the time you build your truck-tractor the type of wiring system or electrical plugs that will be used on the trailer or trailer combinations that might, in the future, be tored by the truck-tractors.

Thank you for writing.