Air cond. compresser don't stay running - 2006 Chevrolet Impala

You did take terminals off battery before replacing alternator? May have blown a couple fuses maybe. Check fuses to lights and air cond. Don't know what kind of car you have if it stalls then you wait a few minutes and it starts back up it could be timing sensor. Need more info.

If the moisture is oily, your heater core could be leaking.
If the moisture is dry, check to see if your ac compressor is running in defrost mode.
The air cond dries the air in defrost mode.

If you mean the condensation water from the a/c - the drain tube is probably gunked up.
There is a small tube or hose near the passenger floorboard that the water drains thru. You should be able to see if from under the truck.

see the schematic and proceed with the troubleshooting and fix it.
God bless you

you might want to recharge your air compresser or the heater coar thats my guess it worked on my truck

Temp is controlled by an electric motor(or could be vacuum hose) on the blender door of heater housing. If you find this is operating correctly, then the problem is a plugged heater core.Backflush it by removing both heater hoses and flushing from water pump side toward thermostat side.don-ohio

Is this an automatic temp. control or manual heater control? if it's automatic control,it can be an expensive circuit board which has gone bad. don-ohio

More info. needed.If you just mean the cooling fan runs at idling,that is normal.If you have the air cond. on,especially on MAX setting, a lot of cars have the fans set to run all the time you are in MAX-AIR setting. don-ohio

Near the firewall you have both air cond pipes coming out. There is a black cap on the larger of the two alum pipes. It is under the air filter housing and should be able to see it without removing the air filter housing. That is the low pressure side.
The high pressure should run along the chassis rail and near the radiator there is another black cap on a smaller alum pipe.
Remember always yes always vacumm the air cond system for at least 3 hours to dry out the air cond system correctly. If you don't if will only work for a short time before playing up again.
Some shops don't do this and wonder why a car keeps coming back for more gas. Good for them bad for customer.

AC's have a low freon switch that shuts off the system to protect the compressor in the advent that you have a freon leak have the system checked for a leak