* High Engine Coolant Temperature: This is the most common reason. When the coolant temperature reaches a predetermined threshold (usually around the normal operating temperature or slightly above), the engine's computer (PCM or ECM) signals the cooling fans to turn on to help dissipate heat and cool the coolant down.
* Air Conditioning Operation: The A/C condenser is located in front of the radiator. When the A/C is running, the condenser generates significant heat. The cooling fans often turn on to help cool the condenser and prevent the A/C system from overheating.
* Low Coolant Level: If your coolant level is low, the engine may overheat more easily. While not directly sensing low coolant, the system might trigger the fans as a secondary protective measure if the temperature starts rising.
* Electrical Malfunction: A faulty temperature sensor, relay, or the fan control module itself can cause the fans to run unnecessarily, even when the engine isn't hot. Conversely, a malfunction could prevent the fans from turning on when needed, leading to overheating.
* Other Factors (Less Common): In some cases, other factors like transmission fluid temperature (if the transmission cooler is integrated into the radiator) might trigger the fans.
If your Windstar's cooling fans are behaving erratically (running constantly, not running when they should, or making unusual noises), it's important to have it checked by a mechanic. Ignoring cooling system issues can lead to serious engine damage.
