1, often wipe the surface of the instrument, on the one hand, to prevent dust and oil invasion of the instrument internal damage to the core, on the other hand, it is also easy to observe the dynamics of the instrument needle.

2, master the performance of the instrument and the instrument indication state and the engine part of the working condition of the relationship, in order to indicate the state according to the instrument to determine the working condition of the engine, find the fault parts and causes.

3, the engine starts, observe the dynamics of the instrument, found abnormal, timely treatment; engine running and car driving, should also be frequently observed the dynamics of the instrument, in order to grasp the work of the relevant systems.

4, the voltage value of different meters, in addition to the ammeter are not allowed to use each other, in order to avoid damage to the instrument.

5, electro-thermal and electromagnetic instrument sensor performance is very different. Such as electrically heated fuel gauge variable resistance sensor, its resistance value with the tank oil plane increases and decreases, while the electromagnetic fuel gauge variable resistance sensor resistance value change is the opposite; electrically heated oil pressure gauge sensor variable resistance value with the oil pressure increases and decreases, while the electromagnetic oil pressure gauge variable resistance value change is also just the opposite; electrically heated water temperature gauge sensor thermistor, water temperature of 50 ℃ resistance value of 220 ohms, water temperature of 50 ℃, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms, the resistance value of 220 ohms. Resistance value of the thermistor of the electro-thermal water temperature gauge sensor, water temperature 50 ℃ when the resistance value of 220 Ω, water temperature 115 ℃ is reduced to 20 Ω, while the electromagnetic water temperature gauge sensor thermistor, in the water temperature of l00 ℃ resistance value is still high, the temperature continues to rise its resistance value is significantly reduced. Therefore, the electrothermal and electromagnetic instrumentation and its sensors should be used in conjunction with, not interchangeable use or separate replacement.

6, the water temperature meter sensor is well grounded, the sensor wire shall not be lap, short circuit, in order to avoid damage to the water temperature meter.

7, when installing the oil pressure sensor, should make the "↑" mark towards the top, otherwise it will reduce the accuracy of the oil pressure gauge indication.

8, electromagnetic fuel gauge should be connected to the lower terminal sensor, the upper terminal is connected to the ignition switch. Otherwise, the pointer will always point to "0".

9, the movement of the float in the fuel tank should be flexible; fuel tank and fuel gauge sensor grounding should be reliable. If the iron is not good, the pointer will always point to "0".

10、When testing the fuel gauge system with electricity, the sensor should not be taken out close to the fuel tank, in order to prevent the contact from sparking due to the sliding of its variable resistance, which may cause the fuel tank to catch fire and even hurt people.

11, the meter circuit is equipped with a voltage regulator, its shell should be reliable iron. When the voltage regulator is damaged, the meter can not be directly connected to the power supply to avoid damage to the meter.

12, ammeter positive and negative polarity can not be reversed. If the car is negative iron, the ammeter "-" terminal should be connected to the battery line (positive), "+" terminal alternator line.

13, ammeter wiring should be gaskets, nuts, bolts and other contact surfaces with sandpaper grinding, installation of nuts, can be coated with a little bit of clean oil, both rust and corrosion and easy to dismantle; plane insulating washers should be intact, and insulating washers and spring washers should be installed between a flat spacer and firmly connected, so as to avoid poor contact with the wire head heating, and even burned instrumentation and wiring harness.

14, regular testing of electrical instruments. Lack of testing instruments, can be compared with the standard meter: ammeter error should be less than ± 20%; oil pressure gauge error, oil pressure of 0.2 MPa should be less than ± 10%, oil pressure of 0.5 MPa should be less than ± 20%.