To be certain:
* Look for the thicker hose: The high-pressure side uses a thicker hose and often has a significantly larger diameter than the low-pressure suction line. The high-pressure line will also often have a drier/accumulator attached to it, which is usually a cylindrical component near the firewall.
* Look for the fitting: The high-pressure fitting is usually larger.
* Consult a repair manual: A repair manual specific to your 1999 Dodge Intrepid will have diagrams clearly showing the A/C system components and their locations. This is the most reliable way to identify the high-pressure side.
Without a visual inspection or a repair manual, it's impossible to give a precise location. Be cautious when working on the A/C system, as it contains refrigerant under high pressure.