AC pipe (gas pipe) freezing up

[rubiohiguey]

Chrysler Sebring, 2001, 2.4 LX. Evaporator and expansion valve replaced recently (heavy gas leaks).

Now, when the AC fan stays on "low" (1 or 2) for some time (e.g. 10 minutes in lower temperatures, 20 minutes when it's hot) I see the odorless vapor coming off the dash vent.

Today I found out (outside temp. about 78 degrees - AC on because of 100% air humidity) with A/C on "1" that the thick pipe (that carries refrigent in the form of gas) has frozen up - it had an ice cap.

I turned on the regular ventilation, and in about 1 minute the ice was gone. I did some testing and the pipe "freezes up" in less than 5 minutes if the fan is on "1" or "2" (with low outside temp). The airflow from the vent is also reduced (cooling can be felt, but very low air flow even on "3" or "4" fan speed). Outside temperature about 78 degrees.
If the fan is on "3" or "4" the thick pipe does not freeze up.

During the noon-time (hot outside), it works quite well with fan on "3" or "2" ("1" is too low to cool at noontime).

One more thing - before the evaporator was changed I know the compressor was cycling on and off - in hot weather it was cycling less, with lower outside temperatures it was cycling more. NOW, the compressor stays on and does not cycle.

Already Tried: testing AC fan speeds.
.
No leaks. Full refrigerant. Holds pressure.

Additional info: No heat. When heat on, the air that blows is a bit warmer, but not hot. AC compressor stays on even if "hot air"/heating is selected.

No coolant leaks, no overheating.


Ideas? Thermostat damaged/not connected properly?