Truck A/C vent blowing out ice?

[Greyman]

Evaporator is icing up. Only way for this to happen......

THIS !!!! I typed condenser but this is what I meant, too many pain pills.

[easeup]

evaporator icing up- low pressure cut off switch bad, low freon , insufficient evaporator air flow by plugged cabin air filter, or evaporator drain plugged

[Airtech]

Evaporator is definitely icing up for this to occur. GM left the old low pressure cycling switch in 2007. An evaporator sensor is used to supply evaporator temperature to the control head. A proper scanner is used to ck for trouble codes in the HVAC module. Reviewing any codes can give a technician a path to follow in diagnosis of this type system. Had one a while back that even the dealer could not fix for icing up. Turns out a new control head had been installed and not programmed properly. Most likely a visit to a very good A/C shop with higher end scanner or a trip to the dealer may be the fix. Trying to fix this system (controls) can be expensive if you guess wrong.