S.C. Code § 56-5-4570
Those sections of this chapter which follow immediately, including Sections 56-5-4580 to 56-5-4620, relating to clearance and marker lamps, reflectors and stop lights shall apply as stated in such sections to vehicles of the type therein enumerated, namely passenger buses, trucks, truck tractors and certain trailers, semitrailers and pole trailers, respectively, when operated upon any highway, and such vehicles shall be equipped as required, and all lamp equipment required shall be lighted at the times stated in Section 56-5-4450, except that clearance and side-marker lamps need not be lighted on any such vehicle when operated within any municipality where there is sufficient light to render clearly discernible persons and vehicles on the highway at a distance of five hundred feet.
S.C. Code § 56-5-4570