2000 Sunfire GT a/c

My sister has a 2000 Sunfire GT. She told me that the air wasn't blowing cold air anymore. The first thing I checked was to see if the compressor was engaging when the a/c was turned on. It wasn't. I pulled the relay out of the power distribution center and checked to see what leads were hot. If you're standing at the driver side fender looking at it where the relay plugs in there are 4 slots. The upper left one is the only one that is hot. I connected a jumper wire between the two upper slots and the compressor engaged. So I figured it was just a bad relay. After replacing the relay it still won't work. I checked all other fuses and everything is fine. What would be the next thing I should check?

Thanks,
Jeremy

Any ideas? Should two of the four terminals be hot with the a/c off instead of just one? The relay is good, so something must not be communicating with the relay. The a/c light comes on when you push the a/c button. I don't think it's the controls, but maybe a wire from the control to the relay?