Interpretation ID: 3133o
Vice President
K-D Lamp Company
1910 Elm Street
Cincinnati, OH 45210
Dear Mr. Ward:
This is in reply to your letter of September 14, l988, asking for a clarification of Federal requirements for the minimum lens area for turn signal lamps and stop lamps.
The understanding expressed in your letter is correct. The SAE materials for turn signal lamps and stop lamps for wide vehicles incorporated by reference in Table I apply to original equipment on vehicles currently being manufactured, and to equipment intended to replace such original equipment. These standards were expressly incorporated to supersede earlier versions of SAE standards for turn signal lamps and stop lamps. However, in recognition that original equipment lamps made to earlier SAE specifications might not be compatible with the electrical systems of vehicles designed to conform to later SAE specifications, the agency adopted paragraphs S4.l.l.6 and 4.l.l.7, allowing the continued manufacture for replacement purposes only, of turn signal lamps and stop lamps designed to conform to earlier specifications. Both sections incorporate in their text portions of the earlier SAE standards. Because the earlier specification for turn signal lamps, J588d, required an effective projected luminous area not less than 12 square inches for turn signal lamps on wide vehicles, this requirement is also specified in S4.1.1.7 for replacement lamps manufactured in conformance with J588d.
In short, your interpretation is correct with respect to turn signal lamps manufactured for installation on vehicles whose overall width is 80 inches or more. Single compartment turn signal lamps designed to conform to SAE J588e need meet only a minimum luminous lens area of 8 square inches. But if a turn signal lamp is manufactured to replace a turn signal lamp that was designed to conform to SAE J588d, its minimum luminous lens area is 12 square inches.
I hope this clarifies the matter for your customer.
Sincerely,
Erika Z. Jones Chief Counsel
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