AC PROBLEMS on 1999 Ford Mustang

The AC on my daughters 99 mustang only blows hot air. The compressor works and the coolant is full any suggestions?

Asked by for the 1999 Ford Mustang
you need to have the freon checked as well as the pressures. take it to a shop for a bid.

Thank you will try
1 more answer , 1 more comment
I had the same problem. They changed out a microchip and it was all fixed!
Do you know what the microchip was called?