Re: Pressure switch necessary on a/c?
Most factory Gm are now not running the exact factory spec
refrigerant change to start with.
upgraded R134a compressor , H/D condenser, R134a evap core ,thermostat used a lot .Poa valve not always used .
accumulator instead of r/drier .
In the auto a/c industry upgrades occur often not just Chevelles . Older GM systems do not perform as well as more modern independent designs by some specialists eg Nippon Denso who supply to the auto industry .
Now if u upgrade properly any poor performing older GM a/c can be improved . Keep in mind R134a is low performing refrigerant compared to R12 . That's why upgrades are needed to compensate in the first place .
Qualified Mechanic with years of a/c specialist experience and the appropriate licensing
If it has had wheels Ive fixed or help fix the A/c . Trains /trucks /buses/small planes /cars .
If it come in the shop I`m not refusing to work on it .