Not knowing the history behind your coupe I'll try to give you a starting point! First thing Install a fully charged battery,(2) Connect a volt meter BETWEEN the battery and the car, remove positive battery cable connect the positive side of your volt meter to battery positive post and negitive side of volt meter to the positive battery cable,with all your acc. and ignition off there should be NO more than 1.5- 2.0 volt draw, if there is you can start removing one fuse at a time until the voltage drops, then you should have a idea what circuit the problem is in! Hope this helps