Interpretation ID: nht75-3.3

DATE: 10/22/75

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Nissan Motor Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of September 8, 1975, to Mr. Berndt requesting an interpretation of the visibility requirements specified in paragraph S4.3.1.1 of Federal Motor Vehicle Safety Standard No. 108.

Specifically, you ask whether a front turn signal lamp which is partially obscured by the radiator grille as shown on a drawing that you enclosed would meet the specified visibility requirements, if . . .

"1. The lamp met the photometric requirements under the state of being equipped on the vehicle.

2. We could easily observe through all the photometric test angles that the lamp was activated."

If condition 1 above is met, the lamp would appear to comply with the visibility requirements of paragraph S4.3.1.1.

For condition 2 above, SAE Standard J588d, incorporated by reference in Standard No. 108, specifies in part that signals from lamps mounted on the left and right sides of the vehicle shall be visible through a horizontal angle of 45 degrees to the left and right respectively. To be considered visible, the lamp must provide an unobstructed projected illuminated area of outer lens surface, excluding that portion of the lens that may serve as a reflex reflector, at least 2 square inches in extent, measured at 45 degrees to the longitudinal axis of the vehicle. If your design meets the specified requirement, the lamp would also be in compliance with the requirements of paragraph S4.3.1.1.

As you were informed in a meeting with Messrs. Leysath and Vinson of this agency on September 8, 1975, it is not necessary that the entire lamp as partially obscured comply with Standard No. 108. If either the upper or lower portion of the lamp meets the photometric and visibility requirements, that is sufficient for conformance. If certification is based upon the lower portion alone, however, the center of the lower portion must be mounted not less than 15 inches above the pavement.

Yours truly,

September 8, 1975

Frank Berndt -- Chief Council, National Highway Traffic Safety Administration

Dear Mr. Berndt: This is to ask your interpretation regarding the visibility requirement stated in S 4.3.1.1 of FMVSS 108.

In the case of the turn signal lamp, installation requirements of SAE J5882 referred to FMVSS 108, states:

When one turn signal is used on each side of the front and rear, visibility of the front signal to front and the rear signal to the rear shall not be obstructed by any part of the vehicle throughout the photometric test angles for the lamp.

Even if a part of the turn signal lamp is covered with the radiator grill as shown in the attached drawing, may we understand under the following conditions that the turn signal lamp meets the visibility requirement?

1. The lamp met the photometric requirement under the state of being equipped on the vehicle.

2. We could easily observe through all the photometric test angles that the lamp was activated.

Your prompt reply to this matter would be greatly appreciated.

Very truly yours,

NISSAN MOTOR CO., LTD. -- Tokio Iinuma, Staff, Safety

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