I've been away for awhile because Sponge Bob (square car) has been working well since we sold it to my daughter. I've bought my wife an 87 244 and I need a little help with the AC system.

Her AC doesn't work at all, though the compressor will come on. No cool air whatsoever. The fact that the comp turns on leads me to believe that there must be something in the system otherwise the low temp/pressure switch would not allow it to come on. Correct so far?

I've gotten my certification so I can buy R-12 and I had a can left over from my Mercedes Diesel (which I run on wvo - used cooking oil - by the way). I don't have gauges. I hooked up the can to the fitting on the comp and opened the valve. Nothing happened. The freon will not be sucked in. After running for 15 minutes, the can and hose are still warm, and there is no hose on the car that is getting the slightest bit cool. When I remove the hose, the schraeder valve lets out something - I assume freon and oil. It didn't seem cool though like I would expect of freon.

What I'm wondering is if there is only air in the system. Can't imagine how that would come about, but why would the comp come on and not cool anything? And why can't I get any freon in the system? Could I possibly have used the wrong fitting?

When I added freon to my Merc, it took a long time, but it did go in. What am I missing?

Thanks in advance for the help!

Also, is anybody here running a diesel Volvo on wvo?