[Code of Federal Regulations]
[Title 49, Volume 4]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR393.31]

[Page 1062]
 
                        TITLE 49--TRANSPORTATION
 
        CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION,
                      DEPARTMENT OF TRANSPORTATION
 
PART 393--PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of Contents
 
    Subpart B--Lighting Devices, Reflectors, and Electrical Equipment
 
Sec. 393.31  Overload protective devices.

    (a) The current to all low tension circuits shall pass through 
overload protective devices except that this requirement shall not be 
applicable to battery-to-starting motor or battery-to-generator 
circuits, ignition and engine control circuits, horn circuits, 
electrically-operated fuel pump circuits, or electric brake circuits.
    (b) Trucks, truck-tractors, and buses meeting the definition of a 
commercial motor vehicle and manufactured after June 30, 1953 shall have 
protective devices for electrical circuits arranged so that:
    (1) The headlamp circuit or circuits shall not be affected by a 
short circuit in any other lighting circuits on the motor vehicle; or
    (2) The protective device shall be an automatic reset overload 
circuit breaker if the headlight circuit is protected in common with 
other circuits.

[33 FR 19735, Dec. 25, 1968, as amended at 53 FR 49397, Dec. 7, 1988]