Hi Michael,
ACC is Automatic Climate Control, one of the five printed factory service manuals. It's part of the CD-ROM manual also. Group 83, Job 300. Click
here for a link to the PDF, but be warned, it's 15MB.
Reverting back to R-12 requires totally flushing the oil out of the system, part of which includes removing the compressor, draining it, and flushing it with clean mineral oil. Then, the condenser, evaporator, and all the lines need repeated flushing with solvent. And then some more flushing. After all that, you flush it some more, then put the correct amount of mineral oil in, pull vacuum, and re-charge with R-12. Simple, eh?
Your vent temps are high, but let's see what happens with the new monovalve. The recirc flap pods require dash removal... figure 10 hours start to finish for a first-time DIY, but by my third or fourth time I had this down to 4.5 hours. If you pull the dash, replace EVERY vacuum pod, so you never have to do it again. I posted this earlier, but here it is again - more info on the dash removal & pod replacement:
http://***************/forum/showthread.php?t=528
There are two types of monovalves for your car, depending on the build date... the earlier type is more expensive (~$120 wholesale) than the later type (~$80 wholesale). I'd consider getting a new one since the price isn't outrageous. Oh, don't forget to use MB or Zerex G-05 coolant... no green stuff.
