Interpretation ID: nht95-1.71

TYPE: INTERPRETATION-NHTSA

DATE: February 16, 1995

FROM: Philip R. Recht -- Chief Counsel, NHTSA

TO: Randall B. Clark

TITLE: None

ATTACHMT: ATTACHED TO 1/17/95 LETTER FROM RANDALL B. CLARK TO OFFICE OF VEHICLE SAFETY COMPLIANCE (OCC 10671)

TEXT: This is in response to your letter of January 17, 1995, to the Office of Vehicle Safety Compliance. You have asked for a clarification of the stop lamp requirements of Motor Vehicle Safety Standard No. 108, specifically S5.1.1.27(a), and Tables III and IV.

Your car "has the normal two stop lamps and has a spoiler with a stop lamp built into it." In addition, it "has a stop lamp mounted inside the back window which is not currently hooked up due to the fact that 'Subaru of America' thinks the procedure is a gainst the law." You would like a statement "that an automobile with four stop lamps is perfectly legal in the United States."

For the reasons given below, the legal situation is of sufficient complexity that we cannot provide a blanket statement of this nature. We shall begin with a possible explanation of Subaru's position. We assume that when you refer to Subaru of America you are referring to the manufacturer of your car. In producing and selling your car, Subaru was obliged to conform to Standard No. 108 (and all other applicable Federal motor vehicle safety standards), and to certify that it conformed to those standard s. The three provisions of Standard No. 108 that you reference above required Subaru to equip your car with a center highmounted stop lamp in conformance with the photometric performance and location requirements of Standard No. 108. Ordinarily, this w ould be the lamp inside the rear window. When a vehicle has a spoiler in the rear deck area as original equipment, a manufacturer will frequently locate its center stop lamp in the spoiler instead, since the spoiler might partially block a lamp located in the rear window and thereby create a noncompliance with Standard No. 108. We surmise that Subaru, to facilitate the production process, found it preferable to equip all cars with a window mounted lamp, and to disconnect it on vehicles where a lamp is in the spoiler. The spoiler lamp thereby became the conforming lamp required by S5.1.1.27.

In this circumstance, Standard No. 108 treats the window mounted lamp as a supplemental stop lamp. There are no requirements for a supplemental center stop lamp; however, under S5.1.3 of Standard No. 108, any supplemental lamp is permissible, provided t hat it does not impair the effectiveness of the lighting equipment required by Standard No. 108. The impairment decision is made by a vehicle manufacturer and is reflected in its certification of the vehicle. For whatever reason, Subaru chose to certif y your car with the window stop lamp disconnected.

We do not know whether this represented an affirmative determination by Subaru that the window mounted lamp would impair the effectiveness of other rear lighting equipment (such as overloading the stop lamp circuit and diminishing the light output of the other lamps). But dealers are reluctant to engage in any activity that might negatively affect a manufacturer's certification of compliance. This reluctance is based upon a statutory prohibition forbidding manufacturers, distributors, dealers, and mot or vehicle repair businesses against "making inoperative" equipment on a vehicle already in use, which was installed in accordance with a Federal motor vehicle safety standard. In our opinion letters, we have generally equated the "impairment" test for new vehicles with the "inoperative" test for those in use. In short, Subaru or its representative could believe that connecting the inoperative stop lamp might create a noncompliance that did not exist when the vehicle was certified, thereby putting the m in violation of the prohibition directed against modification of safety equipment on used vehicles.

Obviously, another manufacturer could leave the original window lamp connected and offer a spoiler one as well, its certification being a representation that one lamp meets all requirements and that the supplementary one does not create an impairment of any of the required rear lighting equipment. In this circumstance, four stop lamps would be "legal" under Federal law.

The prohibition against modifications does not extend to the vehicle owner. However, NHTSA discourages vehicle owners from making modifications that reduce the safety of their vehicles. Moreover, state law may restrict such modifications.

I hope that this clarifies the situation for you.