FAQ

A slender rod or filament of drawn metal

The unit of electrical power. Watts are equal to volts multiplied by amperes.

An instrument-panel display used to inform the driver when something undesirable has happened in the monitored circuit or system, such as an overheated engine or a sudden loss of oil pressure. The driver is required to take action when a warning lamp lights. The action is often to shut down the engine to prevent damage.

A two-in-one test instrument. For convenience, a volt-meter and an ohmmeter are mounted in the same case and share a common readout and test leads.

1. An instrument-panel gauge that measures system voltage. When the engine is not running, the voltmeter indicates battery voltage, which should be 12-13 volts in a 12-volt system. When engine is running, voltmeter indicates total system voltage, or combined voltage output of generator and battery. 2. A test instrument that measures voltage in an electrical circuit. Used to check continuity and determine voltage drop in specific circuits of car’s electrical system.

An electromechanical or electronic device that monitors voltage in the vehicle’s electrical system to control generator output within a narrow range. This provides enough current to operate electrical devices while preventing battery overcharge.

Any condition in a circuit that causes voltage to be reduced. This could be an intentional load or an unintentional drop caused by a faulty or corroded terminal. All wire, no matter how low the resistance, shows at least a trace of voltage drop. The portion of voltage which is consumed in a particular part of a circuit.

The unit of electromotive force is the volt. Voltage forces (or tends to force) a flow of current in a circuit and corresponds to pressure in an hydraulic system. One volt in defined as the electrical pressure which when steadily applied to a conductor having a resistance of one ohm will produce a current of one ampere.

A measure of electrical force, or pressure.

A stripe of a second color applied to a wire insulator to distinguish that wire from another one with the same color insulator. Can be simulated by running a waterproof magic marker along a wire.