Learn by 'trial and error' 
Remember, it best for the AC system to have it switched on all the time. Even in winter time. It will dehydrate the air in the cabin and keep your compressor running and the gasses flowing. It will also prevent your car from smelling nasty due to mold nestling in various parts of the ventilation system.
Remember, it best for the AC system to have it switched on all the time. Even in winter time. It will dehydrate the air in the cabin and keep your compressor running and the gasses flowing. It will also prevent your car from smelling nasty due to mold nestling in various parts of the ventilation system.