Rep Power: 0

I drive a 2001 Honda Civic EX. The power locks and inside light don't work when the car is off. Also, the radio only works when the a/c is on, but even then it cuts on and off. The only way I can get the radio to work is to leave the backup fuse in, but then the fan stays on even when the car is off. So my question is: is something wrong with the wiring or is it something else? And is it something I can fix myself?