In the application of automobiles, the hidden dangers of automobile wiring harness failures are strong, but the failure hazards have great advantages, especially the overheating and short-circuit failures of wiring harnesses, which can easily cause fires. Finding the hidden troubles of the wiring harness in time, quickly and accurately, repairing the faulty wiring harness reliably or replacing the wiring harness correctly is an important task in automobile maintenance, and is an important measure to prevent the occurrence of automobile fire accidents and ensure the safe and reliable use of automobiles.
1. Intuitive viewing method
When a certain part of the car's electrical system breaks down, abnormal phenomena such as smoke, sparks, abnormal noise, burnt smell, and high temperature will occur. Through listening, touching, smelling, and looking, the car wiring harness and electrical appliances can be visually inspected, and then the faulty location can be identified, thereby greatly improving the speed of maintenance. For example, when there is something wrong with the car wire, abnormal phenomena such as smoke, sparks, abnormal noise, burning smell, high temperature and so on often occur. Through visual inspection, you can quickly identify the location and nature of the fault.
2. Instrument appearance inspection method
Use the instruments such as induction fault diagnosis instruments, multimeters, oscilloscopes, current clamps, etc. to diagnose automobile circuit faults. Regarding the electronic control system car, we generally use the fault diagnosis instrument to find the fault code to confirm the measurement of the fault scale; then use a multimeter, current clamp or oscilloscope to specifically check the voltage, resistance, current, or waveform of the relevant circuit to confirm the wiring harness wire problem.
3. Tool viewing method
The test light viewing method is more suitable to check the short circuit fault condition of the wire. When using the temporary light test method, it should be noted that the power of the test light should not be too large. In particular, care should be taken when testing whether the control output terminal of the electronic controller has an output and whether there is enough output to avoid overload damage of the controller. It is best to use diode test lamps.
4. Check method of wire jumper
The jumper method is to use a wire to short-circuit the suspected faulty line, observe the changes in the appearance of the pointer or the working conditions of the electrical equipment, and then determine whether there is a fault in the circuit that is open or bad. Jumping refers to the operation of connecting two points in the circuit with a wire. The potential difference between the two points of the bridged circuit is zero, not a short circuit.