Interpretation ID: nht71-3.10

DATE: 05/27/71

FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA

TO: Ideal Corporation

TITLE: FMVSS INTERPRETATION

TEXT: In your letter of May 4, 1971, to Francis Armstrong you request permission to conduct testing of turn signal and hazard warning signal flashers pursuant to SAE Standard J823b, "Flasher Test Equipment," April 1963.

Federal Motor Vehicle Safety Standard No. 108 incorporates by reference SAE Standard J590b, "Automotive Turn Signal Flashers," October 1965, and SAE Recommended Practice J945, "Vehicular Hazard Warning Signal Flasher," February 1966, both of which specify test circuitry and equipment according to "SAE J823." It is my understanding that the major difference between J823 and J823b, which becomes the appropriate sub-referenced standard on January 1, 1972, is the specification in the latter that "The required voltage tests [for variable-load flashers] with maximum bulb load shall be conducted without readjusting each corresponding power supply voltage, previously set with minimum bulb load." It appears that J823 was written before variable load flashers were in general use and that this is the reason for omission of this specification from J823. Since J823b includes all the requirements of the presently referenced SAE standard, you may proceed to implement it immediately.