In order to turn a shaft with combustion, we need to convert not only chemical energy, but we need to convert a reciprocating motion into a rotational motion. The reciprocating motion is the engine’s piston moving up and down, and the rotational motion is the crankshaft turning. As you can imagine there is a lot of things moving all at once with drastic changes in direction and speed. This process generates a lot of unwanted vibration and movement as a by-product.
To turn your starter, electricity flows from the battery, through the ignition switch, and to the small terminals on the starter solenoid. This electricity causes an electromagnet inside the starter solenoid to connect the two heavy gauge wires and form a complete circuit. High amperage electric flow then goes through your starter, turning your engine’s flywheel.
To measure voltage on a battery for example you first turn your meter to DC Voltage. Place the red probe on the positive terminal of the battery and place the black probe on the negative side of the battery or on a common ground. Your voltage will display on the screen.
Measuring voltage is one of the most common tests a tractor mechanic will conduct as he troubleshoots a system. The presence of the correct voltage will determine if a component is functioning correctly or not. A common voltage test will be of the battery. A healthy battery should read about 12.5 volts, and a battery that is being charged should measure between 13 and 14.5 volts.