location of ac service port

Charge A/C at the low pressure connection which will be on the larger AC tubes and hoses coming out the the firewall and headed to the compressor. Here is a guide that will help. https://www.2carpros.com/articles/air-conditioner-how-to-add-freon Here is a diagram to help.

A High pressure connection B Low pressure connection Please let us know if you need anything else to get the problem fixed. Cheers