Condensers don't freeze up. That's the radiator-like device in front of the radiator where hot gas at high pressure comes from the a/c compressor to cool off and become a warm liquid. Hence, it condenses the gas to a liquid.
The evaporator, the part inside the car where the warm liquid boils and absorbs heat from the incoming air, can freeze when it gets really cold and there's available humidity in the air. It gets cold enough to freeze the moisture when there is insufficient refrigerant in the system.
A/C system refrigerant has a pressure dependent boiling point. It is chosen for various qualities, at least one of which will be the variability of the boiling point to cover a range of useful temperatures. In our case, the boiling point will be kept higher than the freezing point of water by making sure the system pressure remains high enough in the evaporator. If not, then the boiling point will be lower than freezing and can freeze up by freezing the moisture in the air that is blowing through the evaporator. You end up with the evap core becoming a block of frost.
If you are having this problem, you'd probably note the lack of air flow, and when you stop the car you would see a small drip of water from the melting frost over a very long time as the frost slowly melts.
But if you are hearing sloshing, then as above, the drain is probably clogged.
Good luck clearing this up.
Cheers,
PH
