I'm going to throw this out as a possibble, but doubt it. I had the same problem on my wife's 98 GT and couldn't figure anything out until I began some basic trobleshooting. Start by disconnecting the Ngitive battery cable and wire a test light between the cable and the battery post. If the light lights up, you have a draw on the battery. Then, start pulling fuses out until you find the circuit that is causing the draw. (you may want to draw a diagram of where those fuses go, so you don't get lost later.) Then you can nail down the problem. (Her car was the ABS pump, so don't rule anything out until you find the problem.)
If the test light does not light up, you may have a problem with the fuseable link between the alternator and the battery This can be checked by starting the car and using a Digital Volt Ohm Meter (set to read DC volts) and measue the voltage coming out of the alternator and the voltage at the battery. These two readings should be CLOSE to the same number (maybe .5 volts difference). If they are not, then the fuseable link may be bad.
Beyond these two suggestions, you may need to take it in to a shop that specializes in auto electrical systems. They usually have more test equipment than your local mechanic (but not always). Hope this all helps.