AUTOMATIC CIRCUIT-BREAKER: Describes a type of circuit breaker that opens the circuit automatically as soon as certain pre-determined conditions have been met.

ARMATURE: Describes the movable part of a relay system that indicates the presence of electric current.

CIRCUIT: Describes a source of electricity (battery), a resistance unit (headlight, etc.) and wires that form a path for the flow of electricity from the source through the unit and back to the source.

CIRCUIT BREAKER: Describes a protective device that will make and break the flow of current when current draw becomes excessive.

CIRCUIT DIAGRAM: Describes a wiring diagram showing the path of the electrical connections and the various colours of the wires.

CONDUCTOR: Describes the material used to form a path for the flow of current, such as silver, copper, and carbon.

CONSTANT VOLTAGE REGULATOR (CVR):   Describes a device used to maintain a consistent voltage level in a circuit, despite fluctuations in system voltage.

CONTROL WIRE: Describes a wire cable that runs from a knob or lever to a device that operates or regulates.

CORE: Describes the magnetic centre of a coil usually made of iron.

CROCODILE CLIP: Describes a small X-shaped spring clip used to make temporary electrical connections where the two legs of the clip are squeezed, the other two jaws (usually serrated) spring open.  

ELECTROMAGNETIC INDUCTION: Describes how voltage is induced in a coil of wire through moving coil by keeping coil stationary and moving magnetic field.

ELECTROMOTIVE FORCE(EMF) Describes a source of electrical energy required to produce an electric current, produced by devices such as batteries or generators and measured in volts. See voltage.

ELECTRON FLOW: Describes a current produced by the motion of free electrons towards a positive terminal, whose direction is the opposite to that of the current

ELECTRONIC CONTROL UNIT(ECU) Describes a microprocessor and memory with electronic maps, forming the central part of the vehicle's engine management system and its subsystems such as a fuel injection or ignition system.

FERRULE: Describes a cylindrical metal cap (with a hole at each end) attached to the end of the cable outer housing to protect the cable housing from fraying.

FIELD COIL: Describes insulated wire wrapped around an iron or steel core that generates a strong magnetic force field when current flows through the wire.

GROUND RETURN: Describes the return path of an electrical circuit provided by a ground connection.

GROUND STRAP: Describes a braided wire strap used to transfer electricity, which can be found between the engine block and the chassis to overcome the fact that the engine is isolated from rubber mounts.

GROUND WIRE: Describes the wire which runs from the negative post of the battery to the frame on negative ground vehicles. Or which connects the engine to the frame.

HARNESS: Describes a fitting in which all electric wires going to each part of the vehicle are bundled together into a harness.

HARNESS TIES: Describes self-tightening nylon straps used to bundle wires into harnesses that, once tightened, can't be removed unless they are cut.

HARNESS WRAP: Describes one of several materials used to bundle wires into manageable harnesses.

HEAT SHRINK TUBE: Describes a thin, rubber-like hose through which an electrical wire is placed. When the tube is heated, it shrinks to fit the wire, thus protecting the wire and increasing safety.

HIGH ENERGY IGNITION SYSTEM(HEI): Describes an ignition system that provides more ignition power than standard systems.

HIGH-TENSION LEADS: Describes the wires from the ignition coil to the distributor and then from the distributor to each of the spark plugs.

HOLD-IN COIL: Describes an autonomous relay coil energised by contacts that close when the relay withdraws.

HOLOGRAPHIC COMBINER: Describes a semi-reflecting layer embedded in laminated windscreen glass used to host head-up displays.