Where do you charge up the air condition for a 2003 poniac grand prix

There should be ports on the right side of the vehicle hnder the hood. They will have palstic caps. The smaller one is for charging the a/c system. Good Luck

You have to look at the lines (tubes, hoses) the one going from the compressor to the condenser in front of the radiator is the high pressure. The other one is low side. There are probably 2 little upright entry tubes on each line. They look something like a valve stem for a tire and have little caps on them. You have to remove the cap on the low side and attach the guages and filling cans there. A 2003 model probably uses 134a gas as a refridgerant. You can buy a kit at Auto Zone for about 40 bucks --with instructions.

The low pressure side is where you connect to. it should be next to the firewall closer to the drivers side