A/C Issue Clutch 1969 Thunderbird

Had A/C evacuated and pressure tested. All good no leaks. Was slow to kick clutch in was thought to be do to freeze protection switch not putting 12 volts to compressor. Did finally work but only blow through defrost and feet. Next day it would not work. Jumped it off the battery blow ice cold air through the dash vents. Checked power going to freeze protection switch 12 volts then on to wire to the compressor 12 volts. Checked switch using ice it shut off and turn back on. Switch on compressor was also thought to be good on day charged. Any thoughts on what's going on would be great!