What does the fan do when temperatures reach 220 degrees?

The fan activates when temperatures reach 220 degrees to help regulate engine temperature and prevent overheating. This response is a critical aspect of the HMMWV's cooling system, which is designed to maintain optimal engine performance. When the temperature reaches this threshold, activating the fan enhances airflow through the radiator, improving cooling efficiency.

This mechanism is essential for protecting engine components from damage that can occur due to excessive heat. By bringing down the engine temperature through increased airflow, the fan plays a vital role in ensuring the reliability and longevity of the vehicle's engine.