Looking for the a/c lowside port

[dmbfan]

Hi,

I have a 2002 Buick Century Custom. I bought some AC Pro Cold to get my A/C working again, but the website didn't have my car listed. I know very little about cars, hence why I'm here. Where is my a/c lowside port located? A picture would be much appreciated!! I beileve it might be the black cap on the fire wall, but I hear some cars have two a/c ports. Any help would be much appreciated.

Thanks!

 

[MelsRegal]

this has a diagram
http://www.justanswer.com/buick/3ossm-2002-buick-century-custom-cooling-system-ac-cold-air.html#

 

[dmbfan]

this has a diagram
http://www.justanswer.com/buick/3ossm-2002-buick-century-custom-cooling-system-ac-cold-air.html#

Thanks!