TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
Page 355 of 890
TM 9-2320-280-20-1 VEHICLE BATTERIES STARTER SOLENOID STARTER ENGINE MECHANICAL PROTECTIVE CONTROL BOX/ DISTRIBUTION BOX ROTARY SWITCH NEUTRAL SAFETY SWITCH GENERAL DESCRIPTION The Starter Circuit consists of the batteries, starter solenoid, starter motor, rotary switch, neutral safety switch, protective control box/distribution box, and related electrical wiring. The relationship of these parts is shown in the block diagram above, and a simplified functional flow schematic is provided on the foldout FO-8. The starter solenoid and starter motor are enclosed in housings to protect them from dirt, icing conditions, and other road hazards. When the rotary switch is turned to “START,” the starter solenoid is energized. The solenoid contacts close, sending battery power to the starter motor. The battery power causes the starter motor pinion gear to engage the engine flywheel ring gear and the engine cranks. When the engine starts, the rotary switch should be released, allowing it to return to the “RUN” position. This deenergizes the starter solenoid which, in turn, disengages the starter motor from the engine. Solenoid current flows from the rotary switch through the neutral safety switch and protective control box/distribution box to the solenoid. Change 1 2-261 STARTER CIRCUIT WITHOUT STARTER LOCKOUT 2-30. STARTER CIRCUIT TESTS