Wires in automotive wiring harnesses are commonly used with wires with a nominal cross-sectional area of 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 4.0, 6.0, etc. (the nominal cross-sectional area commonly used in Japanese cars is 0.5, 0.85, 1.25, 2.0). , 2.5, 4.0, 6.0, etc. square millimeters), each of which has a allowable load current value, which is used for wires of different power consumers. Take the whole vehicle wiring harness as an example, the 0.5 specification line is suitable for instrument lights, indicator lights, door lights, ceiling lights, etc.; 0.75 specification line is suitable for license plate lights, front and rear small lights, brake lights, etc.; 1.0 specification line is suitable for turn signals, fog Lamps, etc.; 1.5 specification lines are suitable for headlights, speakers, etc.; main power lines such as generator armature wires, ground wires, etc. require 2.5 to 4 square millimeter wires. This only refers to the general car, the key depends on the maximum current value of the load, such as the battery ground wire, the positive power line is a special car wire used alone, their wire diameter is relatively large, at least a dozen square millimeters Above, these "big Mac" wires will not be incorporated into the main harness.