Wire harness fault diagnosis is an important part of ensuring the normal operation of electrical systems. The following are common fault diagnosis methods:

1. Visual inspection method

The visual inspection method is to quickly locate the faulty area through observation, touch, smell, and other methods

For example:

Appearance inspection: Check whether the wiring harness is worn, broken, burnt, etc

.

Abnormal phenomenon: Check for any abnormal smoke, sparks, abnormal noise, burnt smell, etc

.

2. Instrument and Meter Inspection Method

Use professional instruments for precise detection

：

Multimeter: measures resistance, voltage, and current to determine if the circuit is short circuited or open circuited

.

Oscilloscope: Check signal waveform, detect signal distortion or interference

.

Infrared thermal imaging device: detects the thermal distribution of the wiring harness and searches for overheated areas

.

3. Tool inspection method

Test lamp inspection method: suitable for detecting wire short circuit faults, but attention should be paid to the test lamp power

.

Wire Crossing Inspection Method: By short circuiting a suspected faulty line, observe the working status of the equipment and determine whether there is an open circuit or poor contact

.

4. Tensile testing

Check the connection strength between the transmission line and the terminal block to determine if there is a fracture

.

5. X-ray detection

Non destructive testing method can clearly display the internal structure and welding points of the wire harness, and detect process defects such as solder leaks and tin slag

.

6. Electromagnetic interference (EMI) testing

Check if the wiring harness generates excessive electromagnetic interference that affects other devices

.

7. Partition detection

Partition the electrical system and set up contacts, quickly locate the fault area by detecting the voltage of each contact

.

8. On board diagnostic system (OBD)

Use the vehicle's built-in diagnostic system to read fault codes and locate wiring harness faults

.

9. Touch test

By touching or activating the connector, determine if it is working properly

.

10. Functional testing

Connect the power supply of the wiring harness and test whether the control equipment is working properly