Reading Wiring Diagrams — Symbols
Z-GI-9spec tableMX-3 Wiring Diagram booklet. Top-left tab 'Z-GI-9', bottom-right page code 'Z-9'. Symbol-legend reference; symbol glyphs described in text rather than imaged.
Symbols
Symbols
Horn
MeaningGenerates sound when current flows.
Speaker
MeaningGenerates sound when current flows.
Heater
MeaningGenerates heat when current flows.
Speed sensor
MeaningMovement of magnet in speedometer turns contact within sensor on and off.
Ignition switch
MeaningTurning ignition key switches circuit to operate various component. (NOTE) Ignition switch is called engine switch on diesel vehicles.
Relay (1) Normally open (NO)
MeaningCurrent flowing through coil produces electromagnetic force causing contact to open or close. Normally open relay (NO): no current to coil = no flow; current to coil = flow.
Relay (2) Normally closed (NC)
MeaningCurrent flowing through coil produces electromagnetic force causing contact to open or close. Normally closed relay (NC): no current to coil = flow; current to coil = no flow.
Sensor (variable)
MeaningResistance changes with other components operation.
Sensor (thermistor)
MeaningResistance changes with temperature.
Capacitor
MeaningComponent that temporarily stores electrical charge.
Solenoid
MeaningCurrent flowing through coil generates electromagnetic force to operate plungers.
Switch (1) Normally open (NO)
MeaningAllows or breaks current flow by opening and closing circuits.
Switch (2) Normally closed (NC)
MeaningAllows or breaks current flow by opening and closing circuits.
Harness (Not connected)
MeaningUnconnected intersecting harness.
Harness (Connected)
MeaningConnected intersecting harness.
Diode
MeaningKnown as a semiconductor rectifier, the diode allows current flow in one direction only. Cathode (K) — Anode (A); arrow shows flow of electric current.
Light-emitting diode (LED)
MeaningA diode that lights when current flows. Unlike ordinary bulbs, the diode does not generate heat when lit. Cathode (K) — Anode (A); arrow shows flow of current.
Reference diode (Zener diode)
MeaningAllows current to flow in one direction up to a certain voltage; allows current to flow in the other direction once that voltage is exceeded.