I bought my 2004 Scion xb about 2 years ago. From day one, when I first turn on the ac it would blow warm air. Then after 5 to 10 minutes, it blows cold air. This condition only happens after the car has been sitting for a day or so. The AC works immediately once the car has been warmed up, or if the car has only sat for an hour or two. Any ideas on what would be causing this?
I thought maybe it needed more freon if there was a leak but it seems like it would have run out by now. Like I said, this has been happening since I bought it 2 years ago.

 

You may want to have the refrigerant checked. Perhaps the previous owner had it recharged and under filled it.