Every motor vehicle and trailer having a gross weight of three thousand (3,000) pounds and less, including the weight of the trailer and the maximum load, shall be equipped with a signal lamp or signal device which is so constructed and located on the vehicle as to give a signal of the intention to stop which shall be red or yellow in color, and signals of intention to turn to the right or left, all of which signals shall be plainly visible and understandable in normal sunlight and at night from a distance of one hundred feet (100') to the rear but shall not project a dazzling or glaring light; except that a stop signal need be visible only from the rear.
Any trailer having a gross weight of three thousand (3,000) pounds or less, including the weight of the trailer and maximum load, need not be equipped with such turn signal device unless the distance from the steering wheel of the towing vehicle to the left outside limits of such trailer body exceeds twenty four inches (24").
All mechanical signal devices shall be self-illuminated during the period from sunset to sunrise or when visibility is limited as to require the use of lights for safety. (1974 Code)