What causes the engine fan on a c-15 to stay running?

The engine fan on a C-15 may stay running due to a malfunction in the fan clutch, which controls the engagement of the fan based on engine temperature. If the fan clutch is faulty or stuck in the "on" position, the fan will continue to operate regardless of engine temperature. Additionally, issues with the engine's cooling system, such as a malfunctioning thermostat or low coolant levels, can also cause the fan to run continuously to prevent overheating. Checking these components can help diagnose and resolve the issue.