Interpretation ID: 1985-04.4

TYPE: INTERPRETATION-NHTSA

DATE: 10/25/85

FROM: AUTHOR UNAVAILABLE; Barry Felrice; NHTSA

TO: Karl-Heinz Faber -- Vice President, Product Compliance and Service, Mercedes Benz of North America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Karl-Heinz Faber Vice President, Product Compliance and Service Mercedes-Benz of North America, Inc. One Mercedes Drive Montvale, NH 07645

I am writing in response to your letters about the headlamp cleaning systems you intend to install on certain 1986 model year vehicles. Your letters provide information about these systems and their performance. My staff has carefully reviewed the information and how it relates to Standard No. 108. "Lamps, Reflective Devices and Associated Equipment."

Our finding is that headlamp cleaning systems as proposed would be governed by paragraphs S4.1.1.36(b)(3), S4.1.3. and S4.3.1.1. The intent of the requirements in these paragraphs is 1) to assure mechanical aimability of the lamp as installed in the vehicle, and 2) to assure that all photometric performance requirements are met with and without installation of auxiliary vehicle parts or accessories, (and if performance degradation must occur, to assure that an auxiliary lighting device is provided). Additionally, the "fail safe" requirements of Standard 112, "Headlamp Concealment Devices" provides a precedent for a requirement that a headlamp should meet all photometric performances requirements, should a wiper fail.

In viewing your company's systems relative to the requirements, it appears possible to design a replaceable bulb headlamp for a specific vehicle application which includes a wiper type headlamp cleaning system, that meets the intent of the law. This could occur if the headlamp system and cleaning system were designed to meet the requirements together: i.e., the photometric performance requirements of FMVSS No. 108 could be met with the wipers in any achievable position and with any standardized replaceable light source. The system would also have to provide for the wiper to accommodate mechanical aiming. The information presented by you appears to show that the design of your system has taken these needs into account. NHTSA would anticipate that any replaceable bulb headlamp system in such an application would be certified by the vehicle manufacturer to meet the performance requirements using a standardized replaceable light source which has minimum lumen output and which has the filament at the maximum out of position tolerance, any replacement headlamp, and any headlamp cleaning system parts. This would be necessary to ensure that the vehicle would remain in compliance when replacement parts are used.

In consideration of the above, NHTSA believes that replaceable bulb headlamp systems with wiper type cleaning systems designed to be compatible and designed to conform to Standard 108 are permissible under the present Standard.

In summary, NHTSA views the use of the wiper type headlamp cleaning system in conjunction with replaceable bulb headlamps as permissible so long as due care is taken to ensure that the systems are designed to conform together, and can remain in compliance in the event of parts replacement.

Sincerely, Associate Administrator for Rulemaking