Where is the low pressure port of ac system in a 1999 Dodge Durango?

The low-pressure AC port on a 1999 Dodge Durango is typically located on the dryer/accumulator. The dryer/accumulator is usually near the front of the vehicle, on the passenger side of the engine compartment. It's a cylindrical canister, often with a service port on the side. The low-pressure port is usually smaller than the high-pressure port and may be identified by a blue cap or a label indicating "low side."

However, you should visually confirm this by looking at your Durango's AC system. The exact location can vary slightly depending on the specific trim level and any modifications. Consult a repair manual specific to your vehicle's year and model for a diagram and precise location. Working with refrigerant requires specialized tools and knowledge, so if you are not experienced, it's best to have a qualified mechanic service your AC system.