Fan comes on when car is off because of weather heat

This question is for my dad's Buick problem. Engine fan comes on when he is not in running car and that wears the battery down. My idea is to just remove a fuse, is their a fuse that can be removed that would only affect that fan problem? He rarely drives the car anywhere but on his property and has to regularly to keep battery from dying. It's just his backup car.

Thanks