Spring is in the air and so it's time to iron out my A/C troubles. It blows super cold and then starts to wimp out after an hour or so. When it does, the air seems to get damp and just cool (not cold). I'm thinking either the electronics are not regulating it properly and it's getting so cold it's icing up the evaporator, or it's icing internally from moisture in the refrigerant.

If it's moisture in the refrigerant can it be fixed by replacing the seals, installing a new drier/receiver and vaccing and recharging the system? There's an A/C shop with an R-12 license not too far from me.

I've got an extra amplifier or two lying around just in case it's an electronic problem.