1998 Jeep Cherokee A/C problem

It works great for the first 5 minutes and get’s icebox cold. I can almost see my breath then the system starts blowing warm air and stays that way. I’ve had the coolant recharged and the shop tells me there is nothing wrong with it. Of course it works for them. Any suggestions?

Thanks for your time!
-Keith

Can you feel air coming through the vents?

Yeah the blowers work great. It just switches from ice cold to warm humid outdoor air. It acts the same as if you were to gun it to get on a highway and the cold air stops until the motor can catch up if that makes sense.