Auto Air Conditioning & Heater Repair: liquid dripping when air con is on., car air conditioning, coolant level

Question
Yesterday I had my car air conditioning on and after stopping the car I noticed a green coloured liquid running under the car.It looked like coolant. I had a look underneath and it continued to drip for a couple of hours. On closer inspection, there was liquid dripping from a small box on the left hand side of the car. I have a Ford Futura 1996. The coolant level did drop from full to about 3/4. I drove today without the air con on, and no liquid has leaked ever since. What could this be?

Answer
wherever the liquid is dropping from you have a leak.
The material is a mixture of oil and UV dye
The fact that you can see it should mean it is on the high pressure side somewhere
Have it investigated by an experienced a/c specialist and replace the component

Thank you