Originally Posted by tazman

Sam is on the right track here but when you go to pull the terminal off of the battery you have to have one probe touching the post and one touching the terminal while you pull it apart. You have to be sure that the car never looses power while you do your test because there are things that will turn off when they loose power. You should see a current draw with the meter between the terminal and post then you start pulling fuses until the current draw drops.

One of the popular things that can cause this is the relay for the windows that allows them to work after you turn off the car before opening the door. So for a quick test on that turn the key off operate the window a little, then open the door and see if the window still operates.