Why does the fan keep running when the ignition is turned on?
1 Answers
The contacts of the fan relay cannot separate, and there is an error in the coolant temperature sensor signal. Ignition: Most cars have dual anti-theft systems: key anti-theft and electronic password anti-theft. The mechanical lock (key) has its inherent characteristics and involves a probability issue of similarity. However, modern car keys contain a computer chip for electronic password locking. When the key is inserted into the car's ignition, the computer chip in the key and the car's computer engage in a rolling code verification. If the password signals match, the car can be started. Fan Relay: The car's electric fan is controlled by the engine coolant temperature switch and usually has two-speed operation: first-stage low speed at 90 degrees and second-stage high speed at 95 degrees. Additionally, turning on the air conditioning also controls the electric fan's operation (controlled by condenser temperature and refrigerant pressure). There are two types of cooling fans: one is the silicone oil clutch cooling fan, which operates based on the thermal expansion characteristics of silicone oil to drive the fan, and the other is the electromagnetic clutch cooling fan, which uses the principle of electromagnetic field engagement to drive the fan. Coolant Temperature Sensor: Inside the car's coolant temperature sensor is the actual sensor. The lower the temperature, the higher the resistance, and vice versa. It is installed on the engine block and directly contacts the coolant to measure the engine's coolant temperature.
