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Car Wire Harness


The wiring harness for cars is for the transmission of power and signals inside the vehicle. The wiring harness is essential for the engine, car body, instrument panel, chassis, etc. For fuel cars, most of them is low-voltage wire harness transmitting signals and lights power, while for EV cars, high-voltage wire harness is commonly used for driving power transmission.


The composition of automotive wiring harnesses also includes connectors, terminals, wires, positioning cards, covers, seals, etc.



  • Common specifications include wires with nominal cross-sectional areas of 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 4.0, 6.0 and other square millimeters (or nominal cross-sectional areas of 0.5, 0.85, 1.25, 2.0, 2.5, 4.0, 6.0 and other square millimeters), each with allowable load current values, suitable for wires of different power consumption equipment.

  • Taking the entire car wiring harness as an example, the 0.5 specification wire is suitable for instrument lights, indicator lights, door lights, roof lights, etc; The 0.75 specification line is suitable for license plate lights, front and rear small lights, brake lights, etc; 1.0 specification line is applicable to turn signals, fog lights, etc; The 1.5 specification line is suitable for front headlights, horns, etc; The main power lines, such as generator armature wires and grounding wires, require wires of 2.5 to 4 square millimeters.

  • Voltage withstand: DC300V, 10 milliseconds

  • Conduction impedance: ≤ 2 ohms

  • Waterproof grade: IP67

  • Insulation impedance: ≥ 5 megaohms



  • Engine wiring harness. Responsible for connecting various sensors and actuators of the engine, ensuring power and signal transmission between the engine control unit, sensors, and actuators.

  • Body wiring harness. Connect various components and systems of the vehicle body, including lighting, dashboard, air conditioning system, audio system, etc., responsible for the power and signal transmission of these components.

  • Instrument panel wiring harness. Connect the instrument panel and driver control panel, responsible for transmitting various indicator lights, instruments, and control signals.

  • Door wiring harness. Connect electrical components inside the car door, such as central lock, window regulator, speaker, etc.

  • Front wall wiring harness. Along the fender and front bumper frame, connect the front electrical components such as turn signals, front combination lights, horns, etc.

  • Chassis wiring harness. The electrical components that connect the car chassis and body, including the braking system, steering system, ABS system, etc.



  • Copper multi core flexible wire, some of which are as thin as hair. Several or even dozens of flexible copper wires are wrapped in plastic insulated pipes (polyvinyl chloride), which are soft and not easy to break.

  • CAN bus configuration, using a multi-channel transmission system. Compared with traditional wiring harnesses, multi-channel transmission devices greatly reduce the number of wires and connectors, making wiring easier.


Advantages of Ronghua:

  • Customized - customize the length, specifications, color, etc. of the wiring harness according to your drawings or sample requirements, with technical R&D one-on-one service.

  • Free samples.

  • Certification: UL, IPC620, REACH, ROHS2.0, ISO9001, ISO14000, ISO13485, IATF16949.

  • We have our own specialized laboratory for performance verification and quality monitoring of the selected raw materials in the early stage, ensuring that every material launched is qualified;

  • After analyzing the main fault modes and failure modes of terminals and connectors, different models of connectors are selected to adapt to different usage environments and equipment;

  • By reasonably improving and merging circuits and components according to product usage scenarios, and modularizing them differently, to reduce loops and improve the reliability of electrical systems;

  • Design the optimal processing technology according to the product structure, usage scenarios, and characteristic requirements, and ensure the key dimensions and related requirements of the product through molds and fixtures;

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