AC compressor won't turn on
I have an air conditioning unit that was installed 4 years ago. This summer, I turned on the air and the blower unit turned on, but the compressor unit didn't seem to turn on. I checked the breaker outside and it seemed fine. I also checked the wiring and it seemed that both the white and the black wires were both attached to a breaker, but that seemed weird to me because there didn't seem to be anything to ground. So I'm just trying to find out if there's something I'm missing, and if anyone knows what might be the problem. The unit was installed by a friend and so there's not a warranty I'm aware of. Any ideas would be GREAT!!