2004 Ford Taurus AC not working

If all that’s wrong is the compressor clutch is slipping, the clutch can be replaced without replacing the entire compressor.

https://www.rockauto.com/en/catalog/ford,2004,taurus,3.0l+v6+ohv,1425068,heat+&+air+conditioning,a/c+compressor+clutch,6572

And most times, this can be done without disconnecting the compressor from the AC system.

Tester