I have a 99 Taurs that has had similar problems. If you have flushed the coolant and are still getting the light coming on then it most likely is the switch in the tank or the connection to the switch under the tank. A replacement tank is $25-$40 at a parts store and very easy to change. As far as your A/C goes, it may be low freon oil. Again, a simple fix, $25-$40 at a parts store for a recharge can with guage will get you back up and running. Many of the parts stores have on-line repair guides that should help in your repairs.