TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
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TM 9-2320-280-20-1 Change 1 1-42.3/(1-42.4 blank) 1-23.3. GENERATING SYSTEM OPERATION (400 AMPERE DUAL VOLTAGE AL TERNATOR) The 400-ampere dual voltage generating system maintains battery charge and provides electrical power to operate vehicle circuits. Major components of the generating system are: B ALTERNATOR (400 AMPERE) – Is rated at 28 volts at 400 amperes and 14 volts at 50 amperes with external regulator. The alternator assists and recharges the vehicle batteries during operation. A BATTERY GAUGE – Indicates electrical system voltage. It is connected to the electrical system through circuit 567. C PROTECTIVE CONTROL BOX / DISTRIBUTION BOX* – Protects the vehicle electric system in the event battery polarity is reversed. Provides load dump, glow plug operation, and interfacing of engine body harnesses. D CIRCUIT 2 – Sends AC signal, indicating alternator shaft rpm, to frequency switch in protective control box to prevent operation of starter solenoid when engine is running. E BATTERIES – Two 12-volt batteries are connected in a series to provide 24 volts to start vehicle and assist alternator during operation. G POSITIVE CABLE 6 – Provides 28-volt alternator output to maintain charge across two batteries. H CIRCUIT 3 – Connects to negative stud on alternator with engine ground strap to provide a ground circuit to alternator. F POSITIVE CABLE 68A – Provides 16-volt alternator output to maintain charge across the lower battery. CIRCUIT 568 – Senses vehicle voltage, and activates the field current in the alternator circuit to alternator. I * Distribution box provides same function as protective control box except distribution box does not protect against reversal of battery polarity.