1. Check the heater switch: When the water temperature of the car is normal and the heater cannot be used normally, start to check whether the heater switch of the car is in good condition and adjust it to the hot windshield. After confirming that the heater switch is in good condition, proceed to the next test.
2. Test the electronic fan temperature control switch: The key of automobile warm air is the process of engine cooling system transferring heat to the automobile.
3. Temperature controller for detecting water temperature: When the temperature controller of the car is turned on, antifreeze will circulate a lot from the idle speed of the engine, and the heating system will be abnormal.