An Overview of the Basic Knowledge of Automotive Wiring Harness

Definition of Automotive Wire Harness


An automotive wire harness is used to direct current to the electrical components of a car, transmitting signals from the driver to the vehicle and external components.


In human terms, the engine is like the heart of a car, while the automotive wire harness serves as the car's nervous system, connecting all electrical components under one common name.


Wire harnesses are non-molded, flexible components that are highly malleable. The actual installation state can differ significantly from the 3D model.


PSA wire harness types are divided into five main classes:


  • Main Harnesses: These harness and automotive wiring harness pins are mainly located in the engine compartment and the chassis, with very few in the cabin.

  • Cabin Harnesses: These are mainly located in the cabin.

  • Instrument Panel Harnesses: These are located in the instrument panel.

  • Engine Harness: This is located in the engine.

  • Small Harnesses: These include the left and right front door harnesses, rear door harnesses, roof harnesses, rear back door harnesses, antenna harnesses, front bumper harnesses, rear bumper harnesses, positive and negative cables.


Composition of the Automotive Wire Harness:


Connectors, terminals, wires, location cards, covers (tape and tubes), sealing components (sealing plugs and caps), and labels.


  • Wires are cut and pressed into branches using wire cutting machines (single branch, press-fit branch, hinge branch).

  • The wire is divided into different specifications, including 0.35, 0.5, 0.8, 1.0, 1.25, 2.0, 4.0, 6.0, 10.0, 15.0, and 25.0, which are commonly known as wire diameter. Wires of different diameters have different copper wire strands and insulation outer diameters. The diameter of the wire determines its thickness.

  • Wire colors: They include black, brown, red, orange, yellow, green, blue, purple, gray, white, and pink, with each color corresponding to a respective letter abbreviation.

  • Wire types can be classified as B, C, H, G, etc. They can also be classified based on their temperature resistance as T2, T3, or T4.

  • There is also a special type of wire called a shielded wire, which is primarily used to prevent interference.


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AUPINS's main products include high-current charging terminals, charging connectors, energy storage connector, and custom wire harnesses for electric vehicles. These products can be widely used in the fields of clean energy, electric vehicle charging, photovoltaic energy storage, and more.


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