AC never comes on

Hi there. I have an 88 Camry wagon. My AC stopped working, it seems like the compressor never gets power and engages. I was told there was a computer chip that need to be replaced. It worked fine before, with no unusual noises. One day it stopped making cool. Fan blows ok. Any suggestions?

No freon = no running compresor. Have you checked that yet?

Is the system smart enough to know if there is no freon and thus refuse to engage? I don't think it ever engages. I haven't checked the freon because I figured I'd at least be able to get the compressor to engage so I can see the bubbles in the check window.