Battery goes dead when car isnt even on

I have a 2009 Insignia that drains batteries every 2 days. It gets a full charge and Ive done drop tests across both negative and positive posts to the alt. Even disconnecting both the alt and starter motor there is still a 2 amp drain. you can test this as others have said by disconnecting the negative terminal and putting an ammeter in series. Set it to 20 amps and mine reas 2 amps. thats a lot of current but a boot light will draw 2 amps or an interior light or a glove box. But it is none of them. So, with the alternator and starter motor disconnected, the spark plug coil bank all of the interior lights and then pull every fuse in the 3 fuse boxes till you see the current drop to zero. Mine still hasnt so I reverted to the battery fuses under the positive battery cover, there are 4 (100amp) fuses and Im guessing the feed each of the three fuse boards. Disconnecting them one by one I found the drain was on the 1st battery terminal. All I now need do is figure out whats on that circuit and start disconnecting stuff - when I find a wiring diagram. Red heavy wire with blue line . not easy to find these drain problems.

You have something drawing on your battery. disconnect the nevagative cable. hook a test light between the negative cable and negative battery post and pull fuses till the test light goes out. when the test light goes out you've found the circuit that's drawing down your battery. trace the circuit and look for a short to ground or if something on that circuit is staying on.