GLOSSARY OF TERMS AND SYMBOLS

BATTERY
  Stores chemical energy and converts it into electrical energy. Provides DC current for the auto's various electrical circuits.

CAPACITOR (Condenser)
  A small holding unit for temporary storage of electrical voltage.

CIGARETTE LIGHTER
  An electric resistance heating element.

CIRCUIT BREAKER
  Basically a reusable fuse, a circuit breaker will heat and open if too much current flows through it. Some units automatically reset when cool, others must be manually reset.

DIODE
  A semiconductor which allows current flow in only one direction.

DIODE, ZENER
  A diode which allows current flow in one direction but blocks reverse flow only up to a specific voltage. Above that potential, it passes the excess voltage. This acts as a simple voltage regulator.

PHOTODIODE
  The photodiode is a semiconductor which controls the current flow according to the amount of light.

DISTRIBUTOR, IIA
  Channels high-voltage current from the ignition coil to the individual spark plugs.

FUSE
  A thin metal strip which burns through when too much current flows through it, thereby stopping current flow and protecting a circuit from damage.
  A heavy-gauge wire placed in high amperage circuits which burns through on overloads, thereby protecting the circuit. The numbers indicate the cross-section surface area of the wires.

FUSIBLE LINK
  A heavy-gauge wire placed in high amperage circuits which burns through on overloads, thereby protecting the circuit. The numbers indicate the cross-section surface area of the wires.

GROUND
  The point at which wiring attaches to the Body, thereby providing a return path for an electrical circuit; without a ground, current cannot flow.

HEADLIGHTS
  Current flow causes a headlight filament to heat up and emit light. A headlight may have either a single (1) filament or a double (2) filament.

HORN
  An electric device which sounds a loud audible signal.

IGNITION COIL
  Converts low-voltage DC current into high-voltage ignition current for firing the spark plugs.

LIGHT
  Current flow through a filament causes the filament to heat up and emit light.

LED (LIGHT EMITTING DIODE)
  Upon current flow, these diodes emit light without producing the heat of a comparable light.

METER, ANALOG
  Current flow activates a magnetic coil which causes a needle to move, thereby providing a relative display against a background calibration.

METER, DIGITAL
  Current flow activates one or many LED's, LCD's, or fluorescent displays, which provide a relative or digital display.

MOTOR
  A power unit which converts electrical energy into mechanical energy, especially rotary motion.

RELAY
  Basically, an electrically operated switch which may be normally closed (1) or open (2). Current flow through a small coil creates a magnetic field which either opens or closes an attached switch.

RELAY, DOUBLE THROW
  A relay which passes current through one set of contacts of the other.

RESISTOR
  An electrical component with a fixed resistance, placed in a circuit to reduce voltage to a specific value.

RESISTOR, TAPPED
  A resistor which supplies two or more different non adjustable resistance values.

RESISTOR, VARIABLE or RHEOSTAT
  A controllable resistor with a variable rate of resistance. Also called a potentiometer or rheostat.

SENSOR (Thermistor)
  A resistor which varies its resistance with temperature.

SENSOR, SPEED
  Uses magnetic impulses to open and close a switch to create a signal for activation of other components.

SHORT PIN
  Used to provide an unbroken connection within a junction block.

SOLENOID
  An electromagnetic coil which forms a magnetic field when current flows, to move a plunger, etc.

SPEAKER
  An electromechanical device which creates sound waves from current flow.

SWITCH, MANUAL
  Opens and closes circuits, thereby stopping (1) or allowing (2) current flow.

SWITCH, DOUBLE THROW
  A switch which continuously passes current through one set of contacts or the other.

SWITCH, IGNITION
  A key operated switch with several positions which allows various circuits, particularly the primary ignition circuit, to become operational.

SWITCH, WIPER PARK
  Automatically returns wipers to the stop position when the wiper switch is turned off.

TRANSISTOR
  A solidstate device typically used as an electronic relay; stops or passes current depending on the voltage applied at "base".

WIRES
  Wires are always drawn as straight lines on wiring diagrams. Crossed wires (1) without a black dot at the junction are not joined; crossed wires (2) with a black dot or octagonal () mark at the junction are spliced (joined) connections.