What is the reason for only one of the two radiator fans spinning in a Volkswagen CC?
2 Answers
If one of the car's radiator fans is not spinning, you can troubleshoot the issue by following these three steps: Check if the coolant temperature has reached the required level: Most modern car radiator fans operate based on electronic temperature control. Therefore, the fan will only start spinning normally when the engine coolant reaches the specified temperature. If the temperature is too low, the radiator fan will not operate. So, if the radiator fan is not working, the first thing to check is whether the coolant temperature meets the requirement. Check for relay failure: If the coolant temperature is within the required range but the radiator fan still does not work, the issue might lie with the fan relay. A faulty relay can prevent the radiator fan from operating. Inspect the temperature control switch: If the above two aspects are not the issue, then you should check the temperature control switch. Sometimes, faults in this component can also affect the operation of the radiator fan, so it's important to inspect it as well.
As a seasoned mechanic with over a decade of experience, I often encounter issues with Volkswagen CC where only one radiator fan is operating. This situation is usually caused by a faulty fan motor itself, particularly when the secondary fan motor ages or suffers water ingress leading to a short circuit. Alternatively, it could be a relay problem, where the electronic switch controlling the fan has poor contact. Another possibility is a blown fuse—you can check the fuse box under the hood for the corresponding labeled position. Loose or corroded wiring connections are also common culprits, especially in Volkswagens where wiring tends to age quickly. A faulty temperature sensor might also trigger only one fan, as the system activates the other fan only when it deems additional cooling necessary. For DIY checks, start by ensuring the fan connector isn’t loose, then test if the motor is functioning. Ignoring this issue can lead to overheating and engine damage, so I recommend visiting a professional shop for diagnosis and part replacement sooner rather than later—don’t skimp on repair costs.
