Interpretation ID: 7288
President, KC HiLites, Inc.
Avenida de Luces
Williams, AZ 86046-0155
Dear Mr. Brown:
This responds to your letter of May 6, 1992, with respect to your "quad beam" product. You point out that, in normal operation, the headlamp lower beam is extinguished when the upper beam is activated; "quad beam" ensures that the lower beam remains activated when the upper beam is used. We advised you on July 2, 1990, that installation of "quad beam" would be acceptable on certain types of four-lamp headlighting systems. You have now asked whether the device can "legally be used on two headlamp systems, either sealed beam or replaceable bulb type?"
Paragraph S5.5.9 of Federal Motor Vehicle Safety Standard No. 108 states that "[except for certain four-lamp systems enumerated in S5.5.8] the wiring harness or connector assembly of each headlamp system 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." This would preclude installation of the "quad beam" on two lamp headlamp systems.
Sincerely,
Paul Jackson Rice Chief Counsel
ref:108 d:6/15/92