To determine the quality and safety of a wiring harness, the following aspects usually need to be considered:

Appearance inspection: The appearance of the wiring harness should be clean, free of scratches, deformations, damages, and other defects. The surface should be smooth, free from fuzzing and peeling. The color should be consistent and have no obvious color difference. The identification should be clear and visible, and not easily worn or faded

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Dimensional measurement: The length, diameter, insulation layer thickness, and branch length of the wiring harness should meet the design requirements, with an error range typically within ± 5mm, ± 0.2mm, ± 0.1mm, and ± 2mm

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Electrical performance testing:

Conducting resistance test: Measure the resistance of the wire harness when current passes through it to evaluate its conductivity.

Insulation resistance test: Evaluate the performance of the insulation layer of the wiring harness and detect whether there is any damage or breakage to the insulation layer.

Voltage resistance test: Determine the voltage resistance of the wiring harness to ensure safe and reliable operation.

Voltage drop test: Evaluate the voltage drop of the wiring harness when transmitting current to ensure that the wiring harness meets the requirements of the electrical system.

Wire harness grounding test: Check the grounding condition of the wire harness. Good grounding can prevent circuit overload or short circuit

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Environmental adaptability testing: including waterproof performance testing, temperature resistance testing, chemical resistance testing, etc., to ensure the reliability of the wiring harness under various environmental conditions

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Mechanical strength testing: including vibration testing, impact testing, and static loading testing to evaluate the stability and durability of wire harnesses under mechanical loads

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Materials and manufacturing processes: Check whether the materials used in the wiring harness comply with relevant national standards and industry specifications, whether they have good heat resistance, corrosion resistance, and wear resistance, and whether they have good insulation performance

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Safety performance testing: Conduct load testing, short circuit testing, and failure testing to ensure the safe use of the wiring harness under various working conditions

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Standard compliance: Ensure that the design, manufacturing, and testing of wiring harnesses comply with relevant national and industry standards, such as QC/T 29106-2014 technical conditions for automotive wiring harnesses

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Through the above tests and inspections, the quality and safety of the wiring harness can be comprehensively evaluated, ensuring its reliability and stability in various applications.