Interpretation ID: nht90-1.91

TYPE: INTERPRETATION-NHTSA

DATE: MARCH 30, 1990

FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA

TO: SAMUEL KIMMELMAN -- ENGINEERING PRODUCT MANAGER, IDEAL CORPORATION

TITLE: N

ATTACHMT: Letter dated 1-12-90 to Stephen P. Wood from Samuel Kimmelman

TEXT:

This is in reply to your letter of January 12, 1990. ideal is a manufacturer of aftermarket variable load turn signal flashers, certified as complying with Motor Vehicle Safety Standard No. 108, for use as replacements for original equipment flashers.

You call our attention to a turn signal indicator system used in some vehicles over the past few years. The system consists of three indicators that flash sequentially when the turn signal is activated. If a turn signal lamp fails, the flasher changes to a higher flash rate so that the third indicator is not illuminated. This signifies to the driver that the turn signal lamp has failed. HoWever, due to differences in operating characteristics between ideal's flashers and original equipment flashers used in these systems, ideal cannot "guarantee our flashers will provide sufficient 'on' time to allow the dash board indicator arrows to reach the 3rd stage as the corresponding turn signal lamps flash within the requirements" of Standard No. 108. You ask whether Ideal can "list our variable load flashers as replacement flashers for vehicles having three (3) growth stage dash board turn signal arrows?"

If ideal cannot be sure that all its flashers will provide the performance for which the triple indicator system is designed, it would seem appropriate to state that these flashers should not be used in such systems. While use of ideal's flashers would n ot appear to affect the operation of the turn signal system itself, the warning feature of the indicator system might not be realized.

However, these remarks are outside the coverage of Motor Vehicle Safety Standard No. 108. As a manufacturer of replacement equipment, Ideal is required only to certify that its turn signal flashers conform to the requirements of Standard NO. 108, which in this instance are those of SAE Standard J590b Automotive Turn signal Flashers, October 1965, incorporated by reference in standard No. 108. Compliance with these requirements is verified through laboratory testing. There is no requirement in Standard No. 108 that ideal ensure that its flashers are compatible with the design of any indicator system in which they may be used.