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2022

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12

How to maintain the car dashboard


1. Wipe the surface of each instrument frequently, on the one hand, to prevent dust and oil from invading the inside of the instrument and damaging the meter core, on the other hand, it is also convenient to observe the dynamic state of the instrument pointer.

2. Master the performance of each instrument and the relationship between the indicator status of the instrument and the working condition of the relevant parts of the engine, so as to judge the working condition of the engine and find out the fault location and cause according to the indicator status of the instrument.

3. When the engine is started, the dynamic state of each instrument must be observed, and any abnormality found shall be handled in time; When the engine is running and the vehicle is running, the dynamic state of each instrument should also be observed frequently, so as to master the working condition of each relevant system.

4. Instruments with different voltage values shall not be substituted for each other except ammeters to avoid damage to the instrument.

5. The sensor performance of electrothermal and electromagnetic instruments is quite different. For example, the resistance value of the variable resistance sensor of the electrothermal fuel gauge decreases with the rise of the oil level of the tank, while the resistance value of the variable resistance sensor of the electromagnetic fuel gauge changes inversely; The variable resistance value of the electrothermal oil pressure gauge sensor decreases with the increase of oil pressure, while the variable resistance value of the electromagnetic oil pressure gauge changes in the opposite direction; The resistance value of the thermistor of the electrothermal water temperature sensor is 220 Ω when the water temperature is 50 ℃, and it drops to 20 Ω when the water temperature is 115 ℃, while the resistance value of the thermistor of the electromagnetic water temperature sensor is still high when the water temperature is 100 ℃, and the resistance value will obviously decrease when the temperature continues to rise. Therefore, electrothermal and electromagnetic instruments and their sensors should be used together and should not be interchanged or replaced separately.

6. The water temperature gauge sensor must be well grounded, and the sensor wire must not be grounded or short-circuited to avoid damage to the water temperature gauge.

7. When installing the oil pressure sensor, make the "↑" mark upward, otherwise the accuracy of the indication of the oil pressure gauge will be reduced.

8. The lower terminal of the electromagnetic fuel gauge should be connected to the sensor, and the upper terminal should be connected to the ignition switch. Otherwise, the pointer always points to "0".

9. The float in the fuel tank shall move flexibly; The fuel tank and fuel gauge sensor shall be grounded reliably. If the grounding is poor, the pointer will always point to the "0" end.

10. When testing the fuel gauge system with power, it is not allowed to take the sensor out close to the fuel tank to prevent the fuel tank from catching fire or even hurting people due to the spark generated at the contact due to the sliding of its variable resistance.

11. When the voltage stabilizer is installed in the instrument circuit, its shell shall be grounded reliably. When the voltage regulator is damaged, the instrument cannot be directly connected to the power supply to avoid damaging the instrument.

12. The positive and negative polarity of the ammeter shall not be reversed. If the vehicle is grounded to the negative pole, the "-" terminal of the ammeter should be connected to the battery live wire (positive pole), and the "+" terminal should be connected to the alternator live wire.

13. Before wiring the ammeter, the contact surfaces of washers, nuts, bolts, etc. should be sanded clean. When installing the nuts, a little clean oil can be applied to prevent rust and facilitate disassembly and assembly; The plane insulating washer shall be in good condition, and a flat washer shall be installed between the insulating washer and the spring washer and firmly connected to prevent the wire head from heating due to poor contact and even burning the instrument and harness.

14. Regularly inspect electrical instruments. In case of lack of detection instrument, it can be compared with standard instrument: the indication error of ammeter should be less than ± 20%; The indication error of the oil pressure gauge should be less than ± 10% when the oil pressure is 0.2 MPa, and less than ± 20% when the oil pressure is 0.5 MPa.