Interpretation ID: nht90-1.16

TYPE: INTERPRETATION-NHTSA

DATE: JANUARY 12, 1990

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

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

TITLE: N

ATTACHMT: ATTACHED TO LETTER DATED 3-30-90 TO SAMUEL KIMMELMAN FROM STEPHEN P. WOOD; (A35; STD. 108) TEXT:

Several vehicles manufactured in the last several years contain dash board turn signal indicators in the shape of arrows that increase in size, through three (3) growth stages, during the "on" time of the corresponding flashing turn signal lamps. When th e turn signal lamps go "off" the dash board arrow goes "off" and begins the next growth cycle when the turn signal lamps go "on". The dash board turn signal arrow follows the "on-off" cycling of the corresponding turn signal lamps.

In turn signal operation when a turn signal lamp fails the original equipment flasher changes to a higher flash rate, shorter "on" and "off" times, thereby preventing the corresponding dash board indicator arrow from reaching the 3rd growth stage. This is an indication to the driver that a turn signal lamp has failed.

We manufacture aftermarket variable load turn signal flashers and hazard warning flashers, certified as meeting the requirements of FMVSS-108, for use as replacements to original equipment flashers. However, due to differences in operating characteristi cs between our variable load flashers and the original equipment flashers used in these vehicles, we cannot guarantee our flashers will provide sufficient "on" time to allow the dash board indicator arrows to reach the 3rd stage as the corre- sponding tu rn signal lamps flash within the requirements of FMVSS-108.

Can we list our valuable load flashers as replacement flashers for vehicles having three (3) growth stage dash board turn signal arrows?