Interpretation ID: nht88-3.98

TYPE: INTERPRETATION-NHTSA

DATE: 11/03/88

FROM: ERIKA Z. JONES -- NHTSA

TO: ERNIE J. BUNNELL -- VICE PRESIDENT/GENERAL MANAGER PACIFIC T-TOP, INC.

TITLE: NONE

ATTACHMT: 08/30/88 LETTER FROM ERNIE J. BUNNELL TO TAYLOR VINSON; OCC 2485

TEXT: Dear Mr. Bunnell:

This is in reply to your letter of August 30, 1988, to Taylor Vinson of this Office. You have provided diagrams of two types of deck lid spoiler installations, intended as either OEM or aftermarket equipment, and have asked how these relate to requireme nts for the center highmounted stop lamp. You understand that the spoiler itself does not have to meet the lighting standard, but would like to comply if possible.

You are correct that the spoiler itself is not subject to the lighting standard (Federal Motor Vehicle Safety Standard No. 108); however, its installation has the potential for creating a noncompliance with that standard. The basic requirements for the lamp is that it must meet the photometric intensities at each of the test points specified in Figure 10 of the standard, and the visibility (and other) requirements of paragraph S4.1.1.41. Photometric testing is conducted according to SAE Recommended Pr actice J186a, with the photometer at a distance of at least 10 feet from the lamp. Test points lie above and below the horizontal axis of the lamp, and to the left and right of the vertical axis.

According to your first design, the spoiler is "at or below the rear brake light using the 5 degree measurement as a guide." You are correct in taking into account the necessity of meeting the 5 degree down test points. But compliance will be affected b y the location of the lamp and slope of the deck lid as well as the shape of the spoiler. The second spoiler is designed "to go over the horizontal intensity of the light." We interpret this as recognition of the need to meet the test points lying 5 and 10 degrees above the horizontal. Our comments are the same as for the first spoiler. In short, if a spoiler design is not vehicle specific there may be no practicable way for you, as the manufacturer of the spoiler, to determine whether its installati on would create a noncompliance. If your design is vehicle specific, the SAE photometric test could be conducted with the spoiler installed.

The responsibility for compliance with Standard No. 108 is initially that of the vehicle manufacturer. If the spoiler is installed as part of the vehicle manufacturing process, the manufacturer's certification of compliance with all applicable Federal m otor vehicle safety standards would cover the center lamp with the spoiler in place. But the dealer also must ensure that a certified vehicle remains in conformance at the time it is delivered to its first purchaser. Therefore, a dealer could be reluct ant to install a spoiler that is not vehicle specific in the absence of some showing that it does not create a noncompliance with Standard No. 108.

Once the vehicle is sold, the National Traffic and Motor Vehicle Safety Act in effect forbids the dealer, or any motor vehicle repair business, from modifications that affect compliance of equipment installed in accordance with a safety standard. This p rohibition, however, does not extend to the vehicle owner, who may modify the vehicle as (s)he wishes, subject to State laws. We are not aware of any State laws that would forbid spoilers of the designs indicated.

We have enclosed a copy of paragraph S4.1.1.41 and Figure 10 for your information, and appreciate your interest in learning more about Standard No. 108.

ENCLOSURE