vent baffle freezing up ????

[XLT_Explorer]

hey all my ac blows hard cold air for about 20 minutes then it slows down to a trickle but still has cold air. you touch the heater box and it's freezing cold, you turn the ac off for 25 minutes and then it works again. could be be because the baffle inside the heater box is actaully having ice form on it? what could cause this ?

 

[Glacier991]

A low charge can sometime lead to this, but in a FORD orifice valve system it is most often a bad low side cutout switch (Is my guess) and yes you can freeze the evaporator core (which is what you are doing). Replace the low side cutout switch, check your charge state, and I bet the problem goes away.