What Causes One Car Cooling Fan to Spin While the Other Doesn't?
2 Answers
Car cooling fans may have one spinning while the other doesn't due to reasons such as insufficient coolant temperature or a faulty relay. Here are the specific details: Insufficient Coolant Temperature: Most modern car radiator fans operate based on electronic temperature control. Typically, the fan will only start spinning when the engine coolant reaches the required temperature. If the temperature is too low, the radiator fan won't activate. Therefore, if one radiator fan isn't working, the first step is to check whether the coolant temperature meets the requirement. Faulty Relay: If the coolant temperature is adequate but the radiator fan still doesn't operate, the issue might lie with the fan relay. A malfunctioning relay can prevent the radiator fan from functioning properly. Thermostat Switch Problem: If neither of the above issues is present, the next step is to inspect the thermostat switch. Sometimes, faults in this component can also affect the operation of the car's radiator fan, so it's important to examine it as well.
My old car had this exact issue before - the right fan completely stopped working while the left one was spinning just fine. After taking it apart, I found the carbon brushes in the right motor were completely worn out, sparking when powered. Bought a new motor from the auto parts market for just over 100 yuan and replaced it myself - pretty straightforward job. Also, oxidized wiring connectors causing poor contact are common; usually just sanding the connector pins with sandpaper can fix it. Another thing to check is whether the temperature sensor has failed - if the coolant temp signal doesn't reach the ECU, the fan won't know when to kick in. Poor cooling really puts the engine through hell, so get it sorted ASAP.
