Before you start working with the fan, fill it up to "Max" when it's cold and see if the light goes away. If the light goes out, watch the tank when it's cold to see if the level changes.
I don't know if it's common, but my engine compartment temp sensor was out. I got the flashing light and the coolant was fine so I pulled the engine compartment fan and connected it strait to the battery. Fan worked so I replaced the relay (cheap at Radio Shack) to see if it would come on, but no go. Finally, I fiddled around and found the sensor and replaced it and all is good.
If you run the car and it's above 195 coolant temp, turn the A/C on full blast and see if your engine compartment fan comes on. It's on the right (passenger) side behind the door. You can feel and hear it if it's running. If not, you probably have a bad fan, bad temp sensor or bad relay.
The fan's easy to get out, only one 10mm nut holds it in and the wiring harness clips to it. You only have to open the engine compartment to get it out. Relay is in the rear trunk (
http://www.theschillings.com/boxrelay.htm for charts) and the temp sensor is on the right side held in with a grommet that's stuck in the "spider" directly in front of the fan.
If the fan works and you are still slowly loosing coolant, pull the carpet up in the rear trunk and see if there are signs of the coolant tank leak that is common.
