The only thing drawing power should be a clock or stereo's memory circuit. That would probably be about .035 amps. My Cuda, is sitting in my friends garage and has been parked for 6 months and the battery is still ready to crank. No Radio or working clock so it is like being disconnected. To test for current draw, I have a test light soldered to 2 alligator clips that I clip between the positive cable and battery post. The brighter the light, the more the draw. Start unplugging connectors till the light goes out. I use a brake light bulb for finding shorts. The light will grow brightly saving your wires from frying till you find the short. If you can't see the light also use a small 12v buzzer from Radio Shack hooked in parallel to the light. Then you can listen for the buzz to stop while unplugging wires. Some guys don't know a thing about wiring, so they end up paying me $40 a hour to fix dumb stuff like brake lights not working
I had a friend's challenger draining the battery all the time when parked. He told me the dome light "pulsed" when the door opened and the car was off. When I heard that, I knew what it was. I told him that he had his clock wire (constant 12v) plugged into his guage voltage limiter and should be a switched 12v. That fixed it.
Rob