This is my question, the ac in my 2000 Chevy S10 2.2L stopped blowing cold air. the clutch doesn't seem to be engaging. I tried recharging the system but the gauge is up in the red zone already.
If the AC compressor isn't kicking on, the pressure inside of your AC system is equalized throughout the system. This would allow for your gauge to appear in the "red zone" even though the compressor hasn't kicked in.
My thinking is, your system pressure has fallen just below the threshold where the compressor will kick in. You can try and jump the system manual at the pressure sensor with the gauge still on the low side and see where pressure goes to. Run it this way just long enough to detect what the pressure is in the system. If this shows you still have good pressure, your pressure switch is probably bad. If this is the case, you'd need to take it to a shop where they can evacuate the system of refrigerant, replace the switch, and refill to the proper levels.