An A/C fan control module helps to control the blower that supplies air to the cabin of a vehicle, as well as the cooling fans. The module helps to make sure that the cool air that is produced within the A/C system of a car is blown into the cabin. The A/C fans that are mounted in near the radiator of the car are also controlled by this module. Usually, you will have a variety of signs that the A/C fan control module is going out. If the cooling fans begin to run erratically, then you may have a problem with the control module. Letting this type of issue linger can lead to a number of issues that can cause damage to your car. Getting the A/C fan control module replaced can save you a lot of time and money. 1. Cooling fans running for a long time The cooling fans under the hood of your car are designed to keep the components of the system at a lower temperature. Usually, these fans will come on when the system gets a bit too hot and the go off once the desired temperature is reached.