Where is the ac orifice tube located on a 1994 mercury villager van with 3.0 liter engine?

The AC orifice tube on a 1994 Mercury Villager with a 3.0L engine is located within the AC high-pressure line. It's not externally accessible like a drier. You'll need to access it by removing the high-pressure line itself, which requires specialized AC tools and knowledge to handle the refrigerant safely. This is not a job for the average DIYer due to the risk of injury and environmental damage from refrigerant leaks. A qualified auto AC technician should perform this repair.