Interpretation ID: nht80-1.44

DATE: 04/03/80

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Aveco Trucks of North America, Inc

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your request for an interpretation of Federal Motor Vehicle Safety Standard 101-80, Controls and Displays. You described a bulb check button which could be activated at any time by merely pushing it in, but which when released would be automatically deactivated. You asked whether the possible activation of this button at any time would take it out of compliance with section 5.3.1 of Safety Standard 101-80.

This section states that "a telltale shall not emit light except. . . during a bulb check upon vehicle starting." This provision was intended to prevent the driver from accidently leaving the bulb check control activated and thereby creating a situation where a defective functioning of the vehicle would go unnoticed by the driver. Since the bulb check control that you described cannot accidently be left in the on position since it is deactivated when the driver releases it, section 5.3.1 of Safety Standard 101-80 would not operate so as to prohibit use of this device.

I hope that you have not been inconvenienced by our delay in sending you this response.