Saab: 1995 Saab air conditioning, operation hope, refrigerant

Question
Jerry, Help.  I tried to recharge my air conditioner with a recharge kit.  I am on the low side and put the guage on it with out the refrigerant to test the presure.  It is empty.  I then attatch the refrigerant can and it takes about 5 seconds of filling and says it is in the red zone.  It wont take a charge.  NOt sure what this means.

Answer
Frank:
 What you need to do is turn on the a/c  with engine running and then start the recharge cycle. At first the compressor will cycle on and off, mostly off as the system is only partially charged as the compressor draws in the charge from your can of R-134. You can sense that this is occurring if you hold the can upside down and feel it to be cold as the refrigerant runs out and expands. As it charges, the compressor will stay on more and more until it stops cycling and stays on.  Then you have charged the system at its low threshold. Continue to add additional refrigerant to get the gauge in the proper operating level..its a varying pressure at best and do not worry about great stability or accuracy in the pressure readings.  By now the a/c should be nice and cold and operating properly.
  BUT, what caused it to get empty in the first place?  Most likely its the compressor and I am afraid only a rebuilt/new unit will assure future trouble-free operation.

   Hope this helps,
                       Jerry