1. Faulty Coolant Temperature Sensor: The coolant temperature sensor monitors engine temperature and sends a signal to the fan control module to turn on the fan when necessary. If the sensor is faulty, it may not provide an accurate temperature reading, causing the fan to remain off. Check the sensor by disconnecting its connector and measuring the resistance across the terminals. Compare the measured resistance with the specifications in the vehicle's repair manual. Replace the sensor if it's out of specifications.
2. Defective Fan Control Module: The fan control module receives the signal from the coolant temperature sensor and controls the operation of the cooling fan. If the module is faulty, it may not receive or process the sensor signal correctly, resulting in the fan not turning on. Inspect the fan control module for any signs of damage, such as corrosion or loose connections. If necessary, replace the fan control module.
3. Wiring Problems: Check the wiring between the coolant temperature sensor, the fan control module, and the cooling fan for any damage, loose connections, or corrosion. Repair or replace any faulty wiring.
4. Faulty Cooling Fan: Although less common, the cooling fan itself could be defective. Check if the fan motor is receiving power when the air conditioning is turned on. If the fan is not receiving power, the motor may be faulty and需要更换.
Since the cooling fan works when the air conditioning is turned on, it indicates that the fan motor and related wiring are functional. This narrows down the problem to the temperature sensor, fan control module, or wiring related to the coolant temperature sensing system.
Always refer to your vehicle's repair manual for specific testing procedures and specifications related to your Saturn model and year. If electrical testing or repairs are required, it is recommended to seek the assistance of a qualified mechanic or automotive electrician to ensure safety and accuracy.
