94 Grand Prix SE AC Problems

I have a 94 grand prix 3.1L and the AC only blows hot air. It was working and so I thought it was low refrigerant and measured it and it was on the very low side of filled. I tried to put some more in but when hooked up it wouldn't suck any in. Is this a problem with the Compressor? Anyone with any ideas? thanks

you need to check to see if the high side reading is abnormally high, indicating a blocked orifice filter/condenser. Also, if using the 12oz cans, make sure you turn the can upside down when filling, as GM systems take refrigerant as a liquid much better than as a gas.

I will try and check the high side but I think we tried and our gauge wasn't the right size or something. we couldnt get a level. we did try to flip it upside down but it didn't seem like it was doing anything. The in and out hoses both stayed warm. I will give it another try though. If the high side is abnormally high does that mean a blockage and how would i fix that. Thanks