need to know where the lower port is on a 89 Chevy corsica to recharge the air conditioning?

patty your car is a 89 unless someone has changed the a/c over to 134a refridgerent it uses r-12 which you would have to be EPA certifed to handle or buy now if you have some R-12 or its been changed over you charge through the big sized hose it is the low pressure side you will find a screw on type cap similar to what you put air into your tires or if its ben changed over it will look like a sewing thimble

If you are recharging from a kit you bought then just find the service ports. your kit will only fit the low side, and the low side is always the smaller of the 2. once you remove the screw on caps you can see the fitting type and you'll see what came in the kit will only fit the one side.