I'm trying to find out where the low pressure fitting is to recharge my A/C on my 1994 S4. It has the new refrigerant R134 and I bought a recharge kit. I do not have the service manuals yet as I just bought the car. I see a fitting on the front of the condenser and a fitting on the back of the compressor. It is important I do not tie into the high pressure side. Any clues out there. Thanks, Mike