Where is the valve to recharge air conditioning unit in a 1988 Chevy Corsica?

The recharge valve (low-pressure service port) on a 1988 Chevy Corsica's air conditioning system is typically located on the dryer/accumulator. This is a cylindrical component, often black, that's part of the AC system's refrigerant lines.

You'll likely find it near the front of the car, on the passenger side (right side in the US), somewhere in the engine compartment. It might be somewhat hidden behind other components. Look for a low-pressure fitting (usually a larger diameter than the high-pressure port) with a cap. The cap might be blue.

Important Note: Locating the exact position requires visual inspection of your specific vehicle. There is some variability depending on trim level and any aftermarket modifications. A diagram of your specific car's AC system in a repair manual would be the most accurate guide. It's also very strongly recommended to have an experienced technician perform this task. Improperly handling refrigerant can be dangerous.