2002 Mercedes ML500 AC issue

My daughter's car has been sitting for FOUR years. I brought it to my house and intend to bring it back to life. During the time of not being used, several things that used to work then, is no longer working or at least not the way it should.
AC is working when it first start, but after about a minute or so, it changes to only heat coming out. Why?
Please let me know if you know.

[@FORDRANGERFAN]

My guess is it needs a recharge at least but might have a leak. You can buy the stuff to do it yourself if you don't want to take it to a shop.

[@chefgeir]

Thanks for your comment.

[@chefgeir]

No freon leak. Only an electrical/mechanical port in the duct system that that failed.

[@figgiefigueroa7372]

4 years ago????? Seriously 😳😳😳😳😳😳 That needs to be cleaned up and recharge. But you can do it yourself. Take it to the ac guys!!!!

[@chefgeir]

No freon leak. Only an electrical/mechanical port in the duct system that that failed.