Automotive wiring harness is the main network car circuit, connected to the car's electrical and electronic components and allowed to function without the harness does not exist car circuit. At the moment, whether it is high-level luxury car or Cheap ordinary car, in the form of woven wire harness is basically the same, are made of wires, plug-ins and packages Union tape composition, it has to ensure that electrical signals, but also to ensure that the connection circuit the reliability of electrical and electronic components to supply a predetermined current value, to prevent electromagnetic interference on the surrounding circuitry, and to exclude electrical short circuit. Automotive wiring harness from a functional up points, carrying the drive actuator (actuator) of electricity power lines and transmission sensor input command signal line two. Power lines are thick wire transport large current, and the signal line is not carrying power thin wire (optical fiber communications); for example conductor cross-sectional area of ??the signal circuit is 0.3,0.5mm2. In the motor, wire cross-sectional area of ??the element execution is 0.85,1.25mm2, and a power supply circuit with a wire cross-sectional area of ??2,3,5mm2; and a special circuit (starter, alternator, engine ground wire, etc.) is 8, 10,15,20mm2 different specifications. Wire cross-sectional area is larger, the current capacity is greater. Wire selection, in addition to considering electrical properties, but also constrained by the physical properties of the vehicle-mounted, so the choice is very wide. For example, frequent taxi wire on / off between door and across the body, should consist of a good deflection performance wire. In the high temperature portion of the wire used, the general good insulation and heat resistance of vinyl chloride, polyethylene coated wire. In recent years, the electromagnetic shield weak signal circuits is also increasing.