2001 S-series A/C pressure switch

The air conditioning on my SL1 is not working. In troubleshooting it, I have no power to the compressor. From there I found the pressure switch has no continuity. So, the next thing is checking the pressure on the high and low sides. Both sides showed 30 PSI. I'm pretty sure the problem lies there. What I can't find is what PSI each side should be. My knowledge of A/C systems is fairly basic, but if I remember right, the high side should be substantially higher pressure than the low side. Assuming I am correct, what's my next step?

 

I think I goofed up when testing the system. I used the A/C testing kit from AZ under their rent a tool. The directions didn't have any instruction to have the engine running during testing, so I didn't have the engine running. Perhaps that gauge set doesn't require the engine to be running?