Chosen Solution
My 2001 Frontier AC unit runs hot air for half an hour before cold air comes out, and when it does the pressure is good too.
@nassaubay could be a bad compressor etc. Start off with making sure you have enough refrigerant. With AC’s it is hard to make a determination since it requires the proper gauges and testing equipment to do so. Consider having it checked (diagnosed)by a AC shop. Here are some ideas for the basic testing
If you want to go all out, this will definitely help you if you can get the tools. Frontier-HVAC.pdf
