Interpretation ID: nht88-3.50
TYPE: INTERPRETATION-NHTSA
DATE: SEPTEMBER 14, 1988
FROM: RICHARD W. WARD -- VICE PRESIDENT; K-D LAMP COMPANY
TO: ERIKA Z. JONES -- NHTSA
ATTACHMT: LETTER DATED NOV. 3, 1988 TO RICHARD W. WARD, V. P., K-D LAMP CO., FROM ERIKA Z. JONES, CHIEF COUNSEL, NHTSA
TEXT: This is in reference to your letter of Aug. 19, 1988 to Paul Scully regarding the exclusion of reflex reflector area when calculating minimum square inch lens area. Apparently your letter has caused a future customer of KD Lamp Co. to reconsider and rej ect the use of a Turn Signal Lamp of ours which has a lens area of 8 square inches. The following information and enclosed documentation is offered for your evaluation, and I respectfully request your reply to clarify the requirement of minimum square i nch lens area for Turn Signal and Stop Lamps.
In S1. of Purpose & scope FMVSS 108 the standard covers requirements for original and replacement lamps. When a new lamp is designed the requirements of 108 in effect at that time are naturally incorporated into the design. The present requirements of 108 shown in Table #1 for vehicles 80 or more inches wide indicates the applicable SAE standard is J-588e Sept. 1970 for Turn Signal Lamps and J-586c Aug. 1970 for Stop Lamps. Both of these SAE standards in section 3.2 require a minimum lens area of 8 s quare inches (rear lamps) for a single compartment lamp. The device in question meet the J-588e and J-586c, however, our customer has interpreted your letter that 12 square inch minimum lens area is the requirement. Their conclusion is based on the 2nd paragraph of your letter wherein you make reference to S4.1.1.7 of FMVSS 108 and 12 square inch lens area.
It is our position that S4.1.1.7 and S4.1.1.6 of FMVSS 108 is not the present requirements but rather an exception or a permissable use of an old SAE J-588d June 1966 and J-586b June 1966 for lamps used on vehicles manufactured between 1973 and 1978 (ref . page 28238 Fed. Reg. Aug. 6, 1986). If the full context of S4.1.1.7 and S4.1.1.6 is taken into consideration it is apparent the intent, particularly the words "may also be designed", of these sections is to cover vehicles of older manufacture.
After your review of the above and attachments, I would appreciate your comments so the immediate problem as well as any future questions in this regard can be resolved.
Thank You.