Reading Wiring Diagrams
Z-GI-8spec tableSymbols
Symbols
Battery
MeaningGenerates electricity through chemical reaction. Supplies direct current to circuits.
Ground (1)
MeaningConnecting point to vehicle body or other ground wire where current flows from positive to negative terminal of battery. Ground (1) indicates a ground point to body through wire harness.
Ground (2)
MeaningGround (2) indicates point where component is grounded directly to body. Remarks: Current will not flow through a circuit if ground is faulty.
Fuse (1) (box)
MeaningMelts when current flow exceeds that specified for circuit, interrupts current flow. Precautions: Do not replace with fuses exceeding specified capacity. Types: Blade type, Tube type.
Fuse (2) (Cartridge)
MeaningCartridge type fuse.
Main fuse / Fusible link
MeaningFusible link type.
Transistor (1) — NPN (Collector C, Base B, Emitter E)
MeaningElectrical switching component. Turns on when voltage is applied to the base (B).
Transistor (2) — PNP (Collector C, Base B, Emitter E)
MeaningReading code. Example 2SC828A: 2 = Number of terminals; S = Semiconductor; C = type; 828 = number; A = Revision mark. Type code: A = High-frequency PNP, B = Low-frequency PNP, C = High-frequency NPN, D = Low-frequency NPN.
Lamp (3.4W)
MeaningEmits light and generates heat when current flows through filament.
Resistance
MeaningA resistor with a constant value. Mainly used to protect electrical components in circuits by maintaining rated voltage. See resistance value reading below (colored color-band chart and numerical chart).
Motor
MeaningConverts electrical energy into mechanical energy.
Pump
MeaningPulls in and discharges gases and liquids.
Cigarette lighter
MeaningElectrical coil that generates heat.
Reading resistance values <Colored>: Bands are read from the narrow-spaced end (No. 1) toward the wide-spaced end (No. 4). No. 1 and No. 2 give resistance value digits, No. 3 the multiplier, No. 4 the tolerance.
Resistor color band chart
Black
No. 1 (resistance value)0
No. 2 (resistance value)0
No. 3 (multiplier)x 10^0
No. 4 (tolerance)
Brown
No. 1 (resistance value)1
No. 2 (resistance value)1
No. 3 (multiplier)x 10^1
No. 4 (tolerance)
Red
No. 1 (resistance value)2
No. 2 (resistance value)2
No. 3 (multiplier)x 10^2
No. 4 (tolerance)
Orange
No. 1 (resistance value)3
No. 2 (resistance value)3
No. 3 (multiplier)x 10^3
No. 4 (tolerance)
Yellow
No. 1 (resistance value)4
No. 2 (resistance value)4
No. 3 (multiplier)x 10^4
No. 4 (tolerance)
Green
No. 1 (resistance value)5
No. 2 (resistance value)5
No. 3 (multiplier)x 10^5
No. 4 (tolerance)
Blue
No. 1 (resistance value)6
No. 2 (resistance value)6
No. 3 (multiplier)x 10^6
No. 4 (tolerance)
Purple
No. 1 (resistance value)7
No. 2 (resistance value)7
No. 3 (multiplier)x 10^7
No. 4 (tolerance)
Grey
No. 1 (resistance value)8
No. 2 (resistance value)8
No. 3 (multiplier)x 10^8
No. 4 (tolerance)
White
No. 1 (resistance value)9
No. 2 (resistance value)9
No. 3 (multiplier)x 10^9
No. 4 (tolerance)
Gold
No. 1 (resistance value)
No. 2 (resistance value)
No. 3 (multiplier)x 10^-1
No. 4 (tolerance)±5%
Silver
No. 1 (resistance value)
No. 2 (resistance value)
No. 3 (multiplier)x 10^-2
No. 4 (tolerance)±10%
—
No. 1 (resistance value)
No. 2 (resistance value)
No. 3 (multiplier)
No. 4 (tolerance)±20%
Reading resistance values <Numerical>: e.g. printed '332' — First and Second digits give the resistance value digits, the Third digit is the multiplier (x 10^x).