If the temp is below 180F that is why the AC does not run. your t-stat is stuck open. The temp is the problem.
If the engine does not warm up as fast as the computer calculates the AC is disabled. After warm up the temp should always be above 179F.
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Post #2

 

Did the A/C light in the button ever flick on and then go off? Then progress to always black? This is almost always a problem with a low refrigerant charge. Could have too much, if someone tried to fix it with a can. Switch problems possible but less likely. I would take it to a shop with a good reputation for a/c work. Unless it’s never had any refrigerant added. Then, just adding a little might fix you up for years.

These cars are old. They can eventually get a little low with no findable leak. I confess to squirting in 1/2 can with success.