The a/c was working poorly, only a 20degree drop from ambient temps

Question:
I have a 2001 Dodge Caravan, 3.3Liter engine. The a/c was working poorly, only a 20degree drop from ambient temps. The lo side reads 25 psi, the high side reads 50psi., outside air temps in the nineties.The compressor does engage and runs all the time. The system is working partially as a steady drops of water come from the drain.The system runs on 134 and will not take any charging.Any suggestions would be appreciated. Already Tried: Replaced dryer, replaced compressor, evacuated and charged system

Answer;
From the pressures you describe it sounds like the charge is low. If it won't take a charge then you must have a restriction in the system. Most likely the condensor.