Mr. L. W. Camp
Director, Automotive Safety Office
Environmental and Safety Engineering
Ford Motor Company
330 Town Center Drive
Dearborn, MI 48128

Dear Mr. Camp:

This is in reply to your letter of May 28, 1998, asking that we concur in your conclusion that Ford's "Auto Low Beam" feature complies with Federal Motor Vehicle Safety Standard No. 108.

The feature is intended for a vehicle equipped with a two-headlamp system. If the upper beam of one of the headlamps fails, the feature activates the lower beam of that headlamp and notifies the driver.

You point out that paragraph S5.5.9 of Standard No. 108 requires that:

"[t]he wiring harness . . . of each headlamp assembly shall be designed so that only those light sources intended for meeting lower beam photometrics are energized when the beam selector switch is in the lower beam position, and that only those light sources intended for meeting upper beam photometrics are energized when the beam selector switch is in the upper beam position."

You are concerned that S5.5.9 might not allow Ford to manufacture vehicles with the "Auto Low Beam" because the feature would energize a lower beam light source when the beam selector switch is in the upper beam position.

When an upper beam fails, the headlamp system would not meet S5.5.9. It is only when this type of failure occurs that the Auto Low Beam feature activates the lower beam. However, we do not view S5.5.9 as applying to a failure condition.

A supplementary lighting feature such as the Auto Low Beam is subject to the prohibition of S5.1.3 that it not impair the effectiveness of lighting equipment required by the standard. Although there will be an imbalance of headlamp beams when the Auto Low Beam operates, we do not believe that the automatic operation of the lower beam will impair the effectiveness of the upper beam. The Auto Low Beam provides an alternative headlighting system that will function until the safety performance of the original headlamp system can be restored.

In summary, the Auto Low Beam system is permissible as original equipment under Standard No. 108.

If you have any questions, you may call Taylor Vinson of this Office (202-366-5263).

Sincerely,
Frank Seales, Jr.
Chief Counsel
d.7/15/98
ref:108