"Modern Automotive Technology," Vocabulary from Section 5

The charging system reenergizes the battery. Modern cars use an alternator (or ac generator) to induce the current in the output windings. A dead or discharged battery is one of the most common reasons the starting system fails to crank the engine properly.

A parasitic load is any normal accessory circuit current draw present when all electrical devices are shut off (for example, the clock or alarm). If a vehicle sits unused for prolonged periods, the parasitic load can drain the battery enough to prevent starting.

Magnetic fields sometimes build up around a vehicle's body structure (due to antenna mounts, amplifiers, or repeated exposure to high-voltage power lines). This can cause problems with the electronic compass and other devices sensitive to magnetic fields. But this can be reversed with a degaussing or demagnetizing tool.

The main parts of a starting motor are the armature (windings, core, shaft, commutator assembly), pinion drive assembly (pinion gear, overrunning clutch, sometimes a shift lever and solenoid), commutator end frame (for brushes, brush springs, shaft bushing), field frame (for coils and pole shoes), and drive end frame (for pinion gear; has bushing for armature shaft).

An open circuit will keep the electrical components in that section of the circuit from working. This could be caused by a broken wire, disconnected electrical connection, bad switch, or another problem that prevents current flow. A short circuit will show up as a blown fuse, burned fusible link, or open circuit breaker; this results when a hot wire (current-carrying wire) touches ground, which can be caused by cut or ruptured insulation.

The starting motor converts electrical energy from the battery into mechanical or rotating energy to crank the engine.

When a diode is connected to a voltage source in such a way that current passes through, it is forward biased and acts as a conductor. A reverse biased diode connects to a voltage source in a way that does not allow current to pass through; this acts as an insulator.

An oscilloscope will precisely measure the operating voltages of an ignition system. It uses a television-type display screen to show voltage changes in relation to degrees of distributor or crankshaft rotation.

An ignition coil is a pulse-type transformer that is capable of producing short bursts of high voltage (between 4000 and 30,000 volts) to start combustion. The coil produces a low-current, high-voltage surge that jumps the rotor gap, passes through the secondary resistance wire, and jumps the spark plug gap.