Did you ever have the free Special Service Campaign (SSC or SSB) work done on it? Apparently a corrosive substance was in the R12 FREON which caused the expansion valve to leak (may see oil stain in passengers side front wheel wheel are). On my '90 Toyota replaced the expansion valve, seals, evacuated system and recharged with R12 for free. See if yours is covered at ALLDATA>COM or provide dealer with VIN to see if work was done. Think it was SSC001?
Pop the hood and watch to see if your clutch is trying to engauge when you turn your AC on, If it does not pull in 9/10 times your out of freon, usually a leak. There is a low pwessure swith on your system that will not allow it to start below a preset pressure.
Find it jump it out and try again, if it starts and still no cooling you out of gas, if your clutch does not start you may have compressor problems.