A radiator fan has an important role of keeping a vehicle’s engine cool. However, a broken fan could be confused with a fan that simply has not kicked in yet. This is one reason why information on when a radiator fan is suppose to start can be beneficial to vehicle owners.

Time Frame

Temperature will often determine the time that a radiator fan starts up. A temperature-sensitive switch functions to turn the fan on and off periodically. Radiator fans are designed to start when the temperature of the engine coolant reaches around 200 degrees Fahrenheit.