Interpretation ID: 1982-2.15

DATE: 06/14/82

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Carrier Transicold Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 18, 1982, "regarding the legality of placing a red alternator warning light on the side of a truck refrigeration unit."

Because the warning light is not required as original motor vehicle lighting equipment under Federal Motor Vehicle Safety Standard No. 108, it is subject only to the prohibition of paragraph S4.1.3 that it not impair the effectiveness of lighting equipment which the standard requires. The required lighting equipment on the sides of trucks are side marker lamps and reflectors, amber to the front as far as practicable and red to the rear as far as practicable. If the truck's overall length is 30 feet or greater, intermediate lamps and reflectors, amber in color, must be added at or near the mid-point between the front and rear markers.

You have not stated where the warning light will be located, nor the length of the truck on which it would be mounted. To avoid any suggestions of conflict we recommend, if the lamp is to be mounted on a truck carrying intermediate side markers, that it be as close to the rear as practicable. On a short truck equipped with only front and rear side marking devices any location from the mid-point rearward would be acceptable. These locations should also satisfy any questions State authorities may have.

SINCERELY,

May 18, 1982

United States Department of Transportation

Attention: Legal Counsel FMVSS108

Gentlemen:

I am writing you regarding the legality of placing a red alternator warning light on the side of a truck refrigeration unit. The proposed warning light would be a continuous (non-blinking) incandescent lamp, 0.64 inch in diameter. This light would function similar to alternator warning lights found on automobile dashboards, illuminating only when the alternator is failing to charge the battery.

My questions then are:

1. Is red a legally acceptable color for such a light?

2. If red is an unacceptable color, what other colors might also be restricted.

If you require any additional information in answering these questions, please contact me on (315) 432-6168 or leave a message with my secretary on (315) 432-6094.

Thank you for your cooperation.

David R. Siegenthaler Truck/Trailer Engineering