87 260E W124 AC not working

[sjsfiji]

My AC isn't working (not getting cold), but there is air coming out of the vents. I'd like to find out how to troubleshoot the problem... i.e. check which parts should be making noise and/or feel like it's running (please describe locations).

I was told by my brother that it's SUPPOSED to be converted to the new type of AC... i.e. non-FREON... hope it's not a law in CA.

I'd like to do some prelim troubleshooting before I have a mechanic look at it so I don't get zapped.....

thanks.....