1. Detection and judgment of wire harness burnout fault
In the circuit of the power supply system, where the ground is, the wire bundle will be burned, and the junction of the burnt and the intact part can be considered to be grounded; if the wire bundle is burned to the wiring part of an electrical equipment, it indicates that the electrical equipment is faulty.
2. Detection and judgment of short circuit, open circuit and poor contact between lines
The car cable is squeezed and impacted by the outside, causing damage to the wire insulation layer in the wire bundle, resulting in a short circuit between the wires. When judging, the wire harness connectors at both ends of the electrical equipment and the control switch can be disassembled, and the short circuit of the line can be detected with an electric meter or a test lamp. In addition to the obvious fracture phenomenon, the common faults often occur between the wire and the wire terminal. After some wires are disconnected, the outer insulation layer and wire terminals are intact, but the inner core wire and wire terminals of the wires are disconnected. When judging, a tensile test can be performed on the conductive wire and the wire terminal suspected of being broken. During the tensile test, if the insulation layer of the wire gradually becomes thinner, it can be confirmed that the wire is broken. The line is in poor contact, and the fault mostly occurs in the connector. When a fault occurs, it will cause the electrical equipment to not work properly. When judging, turn on the power supply of the electrical equipment, touch or pull the relevant connectors of the electrical equipment, when a certain connector is touched, the operation of the electrical equipment is unstable, indicating that the connector is faulty.
1. Natural damage
The use of automobile cables exceeds the service period, which will cause the wires to age, the insulation layer will be broken, and the mechanical strength will be significantly reduced, causing short circuits, open circuits, and grounding between the wires, causing the wire bundles to burn out.
2. Damage to the wiring harness due to the failure of electrical equipment
When the electrical equipment is overloaded, short-circuited, grounded and other faults, it may cause damage to the wiring harness.
3. Human failure
When assembling or repairing auto parts, metal objects will crush the wire harness, which will rupture the insulation layer of the wire harness; the positive and negative leads of the battery are reversed; when repairing circuit faults, random connection, random cutting of the wires of the wire harness, etc., can cause electrical damage. The device is not working properly.
The first station in the production of automotive cables is the open-wire process. The accuracy of the wire-opening process is directly related to the entire production schedule. Once an error occurs, especially if the wire-opening size is too short, it will lead to rework of all stations, which is time-consuming and labor-intensive and affects production efficiency. The second station after the wire is opened is the crimping process. The crimping parameters are determined according to the terminal type required by the drawing, and the crimping operation manual is produced. For those with special requirements, it is necessary to indicate on the process document and train the operator. Next is the pre-installation process. First, the pre-installation process operation manual must be compiled. In order to improve the efficiency of the final assembly, a pre-installation station must be set for complex wiring harnesses. If the pre-assembled part is assembled too little or the wire path of the assembly is unreasonable, it will increase the workload of the general assembly personnel. The final step is the final assembly process. According to the assembly platen designed by the product development department, design tooling equipment, material box specifications and dimensions, and paste the numbers of all assembly sheaths and accessories on the material box to improve assembly efficiency.
The electronic technology content and quality of automobile cables in the car have gradually become an important indicator for evaluating the performance of automobiles. Car manufacturers should pay special attention to the selection of wiring harnesses, and it is also necessary to understand the process and production of automotive wiring harnesses.