My Radio in my Focus was working fine when I first got it, but it suddenly quit. I purchased a new Radio system and it doesn't work either. I think its a car problem and not a radio problem. I've read that it could be a fuse or wiring problem. Don't know if its relevant, but the security light ( The light above the radio that blinks) only blinks when the engine is off, I know it used to blink all the time. The light on the radio/behind the numbered buttons also blinks when the engine is off and stops when it's started.