I have 97 exp 5.4. When i charge the air it idles up and down. Air still don't blow cold
The ECM is getting the A/C signal, so it is trying to compensate for A/C load that doesn't exist so it drops the in and out, nothing wrong with that. Is the A/C compressor running? If not check the high and low pressures, make sure the charge is correct, and that you have fully operational pressure switches.