Air conditioner not blowing cold air on 1999 Nissan Altima

Works but warm air coming out

Asked by for the 1999 Nissan Altima
Too many possibilities. Low on refrigerant (then whats leaking?), pressure switches (which one?), control head, false sensor reading to computer telling it to turn off. I can go on and on. Take it to a shop and have it diagnosed. It will save you money in the long run to repair the cause than to guess and just put parts in it.