Coolant Leak

Only an experienced guess - the water pump. The seal often leaks just a tad at first, so it takes a while for the leak to show up. Not familiar with the Ford, but if the water pump is accessible feel for the "weep hole" in the pump which is normally located about an inch below the shaft. A paper towel is a more sensitive way of checking... if there is a droplet there or white powder, you should plan to get the water pump changed soon. Some Ford engines are notorious for the water pump seizing and ruining the timing belt, which in turn destroys the engine. You don't want to go that route. If you value your sanity, don't plug the weep hole with anything, as some have been known to do. Your next warning sign is horrible noise from the engine and no go-power.

If the leak isn't from the water pump, it is much less urgent but should not be ignored. Follow the drip upward and see where it takes you. You are looking for a white deposit, which is usually fluorescent under black light, or traces of liquid the same color as the dripped coolant.

Mike

Thanks Mike.

A small leak will evaporate almost immediately when the engine is hot, so you don't see anything when you look. Since the radiator stays pressurized for a while as the engine is cooling, it will continue to drip and once he engine is cool enough, those drops don't evaporate immediately.

Look for the wet spot on the engine in the morning before you start it up. The last time I had this experience on an American car, it was the gasket on the thermostat housing.