TM 9-2320-361-20 1-18. CONTROL SYSTEMS OPERATION The control systems include those controls and their related parts that are essential to the operation of the vehicle. These controls are common to all vehicles with the exception of transfer case power takeoff controls. Each part will be described as part of the following systems: a. Starting System Operation (page 1-38). b. Manifold Heater System Operation (page 1-40). c. Accelerator Controls System Operation (page 1-41). d. Parking Brake System Operation (page 1-42). e. Steering System Operation (page 1-43). f. Clutch Control System Operation (page 1-44). g. Transfer Case Control System Operation (page 1-45). a. Starting System Operation. The starting system will start the engine in all types of weather and has built-in protection that prevents starter engagement once the engine has started. Major components of the starting system are: ACCESSORY POWER SWITCH - Activates all electrical circuits except arctic heaters. STARTER SWITCH - When pressed, provides battery power to starter relay. FUEL PRESSURE SWITCH - Prevents reengagement of starter motor once engine is running. STARTER RELAY - Transfers amperage through starter cables from battery to starter solenoid. BATTERIES - Provide 24-volt battery power to energize starter motor. STARTER SOLENOID - Actuates starter motor gear to crank vehicle engine. STARTER MOTOR - When energized, converts electrical energy to mechanical power as it engages the flywheel to crank engine. 1-38