Interpretation ID: aiam5206
FAX 602-258-5193 Dear Mr. Beidleman: We have received your FAX of Jul 2, 1993, to the attention of Taylor Vinson of this Office, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it pertains to the location of rear identification lamps. The rear configuration of l0 dump trucks that are being constructed for the Arizona DOT is such that you would like to raise the center lamp of the three- lamp identification lamp cluster approximately 1 1/2 inches, the two outer lamps of the array cannot be raised due to the positioning of the underbody tailgate release mechanism. Table II of Standard No. 108 requires that the identification lamps be mounted 'as close as practicable to the top of the vehicle, at the same height, and as close as practicable to the vertical centerline.' In our opinion, the lamps in an identification lamp cluster must be equally spaced laterally and mounted at the same height in order for the identification lamp system to perform its intended purpose. Therefore, I am afraid the agency cannot accept a lamp display that differs. Although the lamps could be mounted on the rear of the cab, we understand that in that position they could be obscured by the top lip of the dump body. We realize that the contractor has pre-punched holes for the lamps, which would be flush-mounted in the rear cross sill of the truck body. If a way were found to cover the holes, there are surface-mounted lamps available which could be mounted at the same height (your desired height for the center lamp) in a manner than should not affect the positioning of the underbody tailgate release mechanism. Sincerely, John Womack Acting Chief Counsel;