As the "nervous system" of electric vehicles, the quality of the wiring harness is particularly important. This article will provide the causes and detection methods of electronic wiring harness failures, hoping that everyone can pay attention.

1. Cause of failure

During the operation of the electronic wiring harness, there will always be failures due to various reasons. Common faults include poor connector contact, short circuit/open circuit/grounding between wires, etc.

1. Natural aging or damage

When the wire harness is used for more than its service life, the insulation layer of the wire harness begins to crack slowly, and the mechanical strength begins to decline. After a long time, it is easy to cause short circuit, open circuit, grounding and other faults between the wires.

2. Wire harness terminal oxidation

When the wire harness terminal is completely oxidized or deformed, it will also cause poor contact or short circuit of the wire harness, thereby causing the wire harness to fail.

3. Failure of electrical equipment

Another situation is that the wiring harness is faulty due to overloading and short-circuiting of electrical equipment.

4. Human reasons

The final cause of failure is improper human operation, such as unreasonable wiring harness installation position, incorrect wiring between wiring harness and electrical equipment, damage to wiring harness components during maintenance, etc.

2. Detection and discrimination

1. Grounding

The rule of electronic wiring harness burnout is: in the circuit of the power supply system, where the ground is, the electronic wiring harness will burn.

At the junction of the burnt and intact parts, the wire can be grounded; if the electronic wire bundle is burned to the wiring part of an electrical equipment, it indicates that the electrical equipment is faulty.

2. Short circuit

The electronic wiring harness is subjected to external kneading and impact, resulting in damage to the insulation layer of the wires in the electronic wiring harness, resulting in a short circuit between the wires, making some electrical equipment out of control and the safety wire blown.

When judging, the electronic 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.

3. Open circuit

For wire breakage faults, in addition to the obvious cracking appearance, rare faults mostly 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 high-temperature-resistant wire and the wire terminal suspected of being broken: during the tensile test, if the wire insulation layer gradually becomes thinner, it can be recognized that the wire has been broken.

The line is in poor contact, and the fault mostly occurs in the connector.

4. Poor contact of 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 touching a certain connector, the operation of the electrical equipment is suddenly normal or abnormal, and the connector is marked. malfunction.