Lilgeo15

Hello, I have a Lexus IS 250 and trying to figure out why my car charging system not working, signal lights not working, and both fans not working and AC gets cold then goes back hot. My dad is a certified mechanic and I wanted to get my Cigarette lighter to work so he changed the fuse which he fixed but when I started back driving the car it started to overheat and my dad checked it again and he say the charging system not working and even though the alternator is reading at around 10 to 11 volts I don’t think it’s the problem and he don’t think it’s the problem either he say it might be something electrical that’s not working. I don’t want to get a new alternator when the signal signals and everything I said above is not working. The emergency lights still work but the signal lights are not working please help with this issue and let me know what I can do.