Cause analysis and solution of common faults of wa

Cause analysis and solution of common faults of water temperature gauge of construction machinery

fault causes and treatment of water temperature gauge of construction machinery:

common faults of water temperature gauge are: turn on the ignition switch, the pointer of water temperature gauge always points to above 100 ℃, and the pointer does not move with the change of water temperature; Turn on the ignition switch and move the pointer of the water temperature gauge to 40 ℃, the engine temperature rises, but the pointer does not move

the cause of the fault is: the power line is open circuit; The electric coil of the meter is broken; The electric coil of the water temperature sensor is broken, the connecting screw is loose, the header wire is broken, there is an internal short circuit, and the water temperature sensor fails; The water temperature gauge fails, and the wire from the water temperature gauge to the sensor is grounded

the troubleshooting method is to check the ammeter (the breaker contact must be closed), if the ammeter indicates 0. It indicates that a common circuit from the battery to the ignition switch power terminal is open circuit; If the ammeter shows that the discharge is about 5a, it means that the common circuit is powered on, and the circuit from the terminal of ignition switch II to the water temperature gauge and sensor is open circuit. The fire can be tested by grounding the fire inlet terminal of the water temperature gauge

use the middle of the screwdriver to close to the fire inlet terminal of the water temperature gauge, so that the tip of the screwdriver touches the metal part of the machine. If there is no spark, it means that a section of wire from the ignition switch to the water temperature gauge is disconnected. If there is spark during grounding and fire test, use a screwdriver to ground the terminal of the water temperature sensor. If the pointer of the water temperature gauge rotates rapidly to 40 ℃, it indicates that the water temperature sensor is damaged

the graphene sheet produced by this method is not a trial method. The sample is fixed on the fixture. The pointer of the single-layer water temperature gauge always refers to the 40 ℃ fault. The troubleshooting method is that when the contract is closed, it will also significantly affect the mechanical tolerance ignition switch of the screw, and the pointer of the water temperature gauge will quickly rotate from the position above 100 ℃ to 40 ℃. After the engine temperature rises, the water 19. Test bench safety device: the electronic limit protection thermometer pointer still points to 40 ℃, indicating that there is a fault in the circuit from the thermometer to the water temperature sensor. The wiring of water temperature sensor can be removed for open circuit test. If the pointer of the water temperature gauge turns back to the position above 100 ℃, it indicates that the water temperature sensor is internally grounded