how to Test and inspection of auto wiring harness

2021-11-30
Test and inspection of auto wiring harness

1. inspection of wiring harness before use

Before replacing the faulty harness, especially in the production unit of auto wiring harness, it is necessary to detect the quality of the harness itself to ensure that the harness is free from unqualified phenomena such as short circuit, open circuit and damage of insulation protective layer. The detection requires batch operation with advanced special detection instruments to ensure the accuracy and speed of detection.

2. inspection after harness replacement

After replacing the harness, first check whether the connection between the cable connector and electrical parts is correct and reliable, and whether the circuit wiring is restored according to the electrical circuit diagram. Then conduct the power on test. First, connect the detection lamp in series between the negative pole of the battery and the frame grounding, and turn off the electrical parts of the vehicle. At this time, if the detection lamp is not on, it indicates that the circuit is normal; Then remove the detection lamp and replace it with a fuse. Without starting the engine, connect the power supply of the electrical parts of the car one by one, and test the wires one by one. After confirming that they are all normal, remove the fuse and connect the grounding wire.
With the rapid development of automobile industry and the improvement of people's living standards, the number of private cars is increasing day by day. The safety performance of cars affects the quality of people's daily life. Automobile harness fault is one of the common faults in automobile faults. Professional maintenance personnel should control the quality of automobile harness itself and the correctness of wires connection, understand the types and causes of automobile harness fault, and then use correct judgment methods to judge, detect and repair the fault, so as to improve their work efficiency and quality, Ensure the safe driving of the car.
With the development of society, people have higher and higher requirements for automobile safety, comfort, economy and emission, automobile harness has become more and more complex, and the correct detection of automobile harness has become more and more important. Next, let's introduce the automobile harness test!

Automobile harness is the main body of automobile circuit network, which is composed of wires, terminals, connectors, sheaths and other materials. The harness is bound to form circuit components connecting automobile electrical and electronic components. The vehicle harness is distributed in the engine compartment, chassis, headlight, air conditioner, instrument panel, seat, ceiling, door, body, trunk, tail lamp, license plate, bumper, battery, etc. Car harness is like human nerves and blood vessels.

The purpose of automobile harness test is to solve the poor contact of connectors, short circuit, open circuit and leakage between wires, and the failure of the overall insulation and withstand voltage level of wires (degradation of skin performance, insufficient insulation performance between solder joints, etc.), so as to avoid accidents.

Automobile harness is divided into:

Low voltage wire harness and high voltage wire harness.

The automobile low-voltage harness, also known as automobile wire, has a voltage range of 60-600v. The low-voltage harness is used for the transmission of current on the automobile battery and is an important part of the automobile. The low-voltage harness is arranged in all corners of the whole vehicle. The damage of the low-voltage harness directly affects the electrical performance of the automobile. Safety is the main consideration in the design of automobile low-voltage harness.

The automobile high-voltage harness is a kind of "wire" with "insulation" device that transmits electric energy through the ignition coil for spark plug ignition, which will make the engine work. Its structure is not complex. A layer of high-strength insulator is wrapped outside the internal metal wire through the production process. It can have good insulation, internal transmission and conductivity at high and low temperatures.

Low voltage harness - test items

1. Visual inspection

2. Dimension measurement

3. Tensile and tear test

4. Cross section inspection

5. Bending test

6. Voltage drop test

7. Circuit test

8. Waterproof test of conductor crimp

9. Waterproof test of terminal heat shrinkable pipe

10. Sealing test of rubber parts

11. Connector waterproof test

12. Conductivity test

13. Vehicle carrying durability test
 
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