Hi all, I need HELP 1994 C280 Air conditioning. I'm pretty sure the system is low on r134a, I have a pressure gage but for the life of me I can't figure out where is the low pressure side connection to check. I have done this on several cars and I feel stuipid just asking but I just can't find it ...

Please advise where is the low pressure side connector on a 1994 C280 and if you happen to have a picture that would be greaaat

You can email me directly at ferrari3@gmail.com if you want

MANY THANKS IN ADVANCE