It is under the dash on the driver side.
look for the port with the black cap on it, it's the low pressure port.
on the evaporator / dryer
You can add Freon to your 1999 Chevy cooling system through the low pressure port. Connect your Freon bottle to the low pressure port and release the Freon into the system.
The smallest with a green cap on it.
The 2002 Chevy Cavalier low side service port can be found on the top of the air conditioner compressor. The low side service port will be labeled as the low pressure port.
Follow lines from compressor-Larger line is low pressure--port may be at or around the accumulator/drier by passenger firewall
It's right above the high pressure port!! :) under the air cleaner box ,
use a pressure guage hooked to the scrader port on the fuel line.
The low pressure service port on your Chevrolet K 1500 air conditioning compressor will be the one closest to the front of the engine compartment. The low pressure service port should be labeled.
Not sure what your asking yes you charge from the low pressure port it is the smaller one your hose should not fit on the high pressure side
In the low pressure service port, the smaller of the two.