TM10-3930-660-20 1-18. ELECTRICAL  SYSTEM BATTERIES . Provide power for three circuits; the charging circuit, the starting circuit, and the lighting circuit. TWO 12  volt  batteries  are  connected  in  series to provide starting power. ALTERNATOR. The 24 volt, 65 amp alternator, an integral part of the charging circuit, provides current when the engine is running. STARTER  MOTOR. Part of the starting circuit, the starter motor is used to turn the engine flywheel fast enough to start the engine running. CIRCUIT BREAKERS. A switch that opens the battery circuit if there is a shorted, ground wire, or excessive current draw by a defective component in the corresponding circuit. When the circuit is open, no current will flow through the electrical system. The circuit breakers will reset once they cool. If a breaker continually trips, the electrical system requires repair. 1-11