(a) All school buses shall be equipped with spare fuses of each size used.

(b) All interior wiring for Type 1 school buses constructed after January 1, 1953, and Type 2 school buses constructed on and after July 1, 1970, shall be concealed, and all exposed wiring shall be protected with a waterproof insulation.

(c) The wiring of each Type 1 school bus constructed after January 1, 1953, shall be arranged in at least ten circuits: (1) starting, (2) ignition, (3) headlamps, taillamps and dash lamps, (4) stop lamps, (5) flashing red/amber lamps, (6) turn signal lamps, (7) clearance lamps and/or side-marker lamps and stepwell lamps, (8) interior lamps, (9) heaters, defrosters, etc., and (10) horn. Each circuit except ignition circuits shall be protected by a separate fuse or circuit breaker with a rating no greater than the safe capacity of the circuit. Fuses, circuit breakers, flashers, pilot lamps, and switches shall be mounted in accessible locations. Head lamps and tail lamps shall be illuminated by a common switch.

(d) Ignition circuits on all school buses manufactured after July 1, 1980, shall incorporate a key-type switch that will stop the engine when the switch is turned to the off position.