Join Date: Apr 2005
Location: Irwindale, CA USA
History: several years ago I had a series of discussions with an engineer email friend who had installed R12a in his GTV6 which I've assumed has about the same 'volume as the Alfetta's. 12a is a combination of propane and isobutane and is compatible with both 134 and older R12 systems. He has advised me on a number of the issues, but for the life of me I can find no place where he said that the low side should be 35 and the high side should be between 350 - 400 psi, however that is how I have those areas marked on my gauges. I'm sure I would not have used these marks without this fellow's advice.
I'll add that, for now, I'm at a loss as to how I have the high side switch on the dryer wired, except I know the black wire goes to 85 (which in turn goes to ground) on the A/C relay. The original A/C did not have a thermal switch.
The condenser comes on and stays on when the compressor is switched on. I'll add that I don't believe that the compressor cycles on and off - perhaps because the vent never gets below 60 degrees.
The A/C as it is now simply does not 'feel' right in that it wants to kill the engine if not kept at the very least 1000 rpm and the car overheats even when moving. Prior to this with the old condenser, it also needed to be kept close to 1000, but if the engine died, it didn't go into the convulsions that it now does. I'm no longer using the A/C until I get things sorted out.
FWIW, one 6 oz. can of 12a is equivalent to 18 oz. of R12 (or 16 oz. of R134).
Question: When adding oil, does that count towards the system's 'volume'?