The cross-sectional area of the conductor used in the motor and the execution element is 0.85 and 1.25mm2, while the cross-sectional area of the conductor used in the power circuit is 2, 3 and 5mm2. And special circuit (starter, alternator, engine grounding wire, etc.) has 8, 10, 15, 20mm2 different specifications. The larger the cross-sectional area of the wire, the larger the current capacity. The choice of electric wire, in addition to considering the electrical performance, but also by the vehicle physical performance constraints, so the choice range is very wide. For example, the frequently open/closed doors in a taxi and the wires that span the car should be made of well-flexed wires. In high temperature parts of the use of wire, generally use good insulation and heat resistance of vinyl chloride, polyethylene coated wire.

In recent years, electromagnetic shielding lines used in weak signal circuits have been increasing. With the increase of automobile functions, the widespread application of electronic control technology, more and more electrical parts, more and more wires, the number of circuits and electricity consumption on the automobile significantly increase, the wire harness will become thicker and heavier. This is a big problem that needs to be solved. How to make a large number of wiring harnesses in the limited car space how to arrange more effectively and rationally, so that the car wiring harnesses play a greater role, has become a problem facing the car manufacturing industry.