AC and Heat

When I turn my car off after having the air run the fan continues to run. I've had the blower motor resistor replaced three times and the control head once. The people who fixed both said they didn't know what was wrong with it. I would have to take it to a dealer. I would like to to see if there is another right bedsides that because dealers are expensive and wasn't sure if oter places could diagnose as well as repair whats wrong. I haven't ran the air or hear in my car for a couple months because the fan that continues to run even when my car is off kills my battery and then I have had to have my car jumped. Hopefully I can get some answers.