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2022

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How to eliminate the fault of the instrument panel


1. Thread-breaking method

When the reading of the automobile electrical instrument is abnormal, the wire inside the sensor or between the sensor and the indicating instrument may have a grounding fault through analysis and inference, the wire removal method is often used for inspection. That is, the cause and location of the fault can be determined by removing the wires on the relevant terminals. Take the electromagnetic fuel gauge as an example. When the internal grounding or float of the sensor is damaged, and the wire between the sensor and the fuel gauge is grounded, no matter how much fuel is in the tank, after the ignition switch is turned on, the pointer of the fuel gauge always points to "0". At this time, the wire removal method can be used for inspection. First, remove the wire on the sensor. If the pointer of the fuel gauge moves to the "I" position at this time, the internal grounding wire or float of the sensor is damaged; If the pointer still points to "0", remove the sensor terminal wire on the fuel gauge. If the pointer moves to "I", ground the wire from the fuel gauge to the sensor; If the pointer still does not move, it may be the internal damage of the fuel gauge or the open circuit of its power line.

2. Grounding method

When the reading of the automobile electrical instrument is abnormal, the sensor may be poorly grounded or damaged through analysis and inference, and the wire between the sensor and the indicator has an open circuit fault, the grounding method is often used to check. The cause and location of the fault can be determined by grounding the relevant terminal with a wire. After the ignition switch is turned on, the pointer of the electromagnetic fuel gauge points to "I" no matter how much fuel is stored in the tank; For the bimetallic fuel gauge, the fuel gauge pointer points to "0". The above conditions indicate that the sensor of the corresponding instrument may be grounded poorly or damaged, or the wire between the sensor and the indicating instrument may have an open circuit fault. At this time, the grounding method can be used to check. First, connect the terminal between the sensor and the wire to the ground. If the pointer rotates, it indicates that the sensor is damaged or the ground is poor; If the pointer does not rotate, the wire can be used to ground the wire post connecting the sensor on the indicator. If the pointer rotates, there is an open circuit fault in the wire between the sensor and the indicator; If the pointer still does not turn, it indicates that the internal indicator is damaged or its power line is open circuit.

3. Shorting method

When other electrical instruments work normally and only the instruments connected to the voltage stabilizer (such as fuel gauge, electromagnetic water temperature gauge, etc.) do not work, the short circuit method can be used for inspection. Short-circuit the input and output terminals of the voltage stabilizer with wires. At this time, if the instrument pointer connected to the voltage stabilizer immediately deflects, it means that there is a fault inside the voltage stabilizer.