Blower motor

So I have an issue with my fiance' s car, the air and fan would not turn on, nor would the windows go down. Previously, the air blower would not turn off, even with the key out of the car. We had just pulled the fuse out to make the blower stop. Also, the air would not turn off, just low and high. So once the air stopped completely, I assumed it was the blower. Then after looking around, I decided I thought it was the ignition switch. I unplugged the battery, unhooked the switch and plugged it back in. Hooked the battery back up and it worked. Still only low and high, but it had air that turned off when the car was off. Windows worked too. I took it for a spin, ran into a store [car off obviously] and drove back home with no issues. My girl goes to move the car while I am in the shower and when she turns it back off, the horn starts blaring, even once the key was out. So I ran out in my towel and unhooked the battery which stopped the horn. I am thinking the issues are all related, but I would love some input and advice.