49 C.F.R. § 393.23 Power supply for lamps.
Title 49 - Transportation
All required lamps must be powered by the electrical system of the motor vehicle with the exception of battery powered lamps used on projecting loads. [70 FR 48046, Aug. 15, 2005]
Title 49: Transportation
PART 393—PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION
Subpart B—Lamps, Reflective Devices, and Electrical Wiring
§ 393.23 Power supply for lamps.
