Heat/ac fan turning on when car is off and locked.

It sounds like a it might have a sticking relay. It's impossible to be sure because I am not there to test it. You probably need to take it to a repair shop. Electrical issues can be hard to find and impossible if you don't know what you are doing. The person checking in out must find where you power is coming from so they have to start at one end of the circuit and trace it back. I decent mechanic should be able to fix this fairly easily. And a lot of the people who answer these questions don't know anything about cars. They are electric repair technicians, they work on phones and tablets. I just happened to be a mechanic for 35 years and had a stroke from an infection and currently can't walk without a Walker. So I taught myself to repair iPhones. So I happen to know how a car works. But in my opinion you would be better off taking it to a local repair shop. Ask around for a place that does quality work and are fair to there customers. Don't go with someone just because they are cheaper, remember you get what you pay for. And a good mechanic will probably fix it cheaper than a cheap shop who uses backyard mechanics that never learned how to do it correctly.