Cadillac Repair: AC charge-1989 Cad Sevile, possability, computer displays

Question
My computer displays shows low refrig...I have some R12 but can only see one spot to fill on the high pressure (skinny line). Can't locate nipple for low pressure line. Where is it at.

Answer
Hi Tom, There should be a port on the line up by the RH side near the firewall. With your car the evaporator cores develop leaks and adding freon might be a short term fix. It might be better to have a shop check for leaks before you add a can or two because at $40+ a pound I would want to know where the leak was so I didn't have to keep adding freon. There is a possability that a sensor could be bad and reading incorrectly. Did you put gages on it to see what the pressures are on the low and high sides? Bill