Although ILUVMILS has described it already, let me tell you how my neighbor and I found a small draw on a 78 Honda.
With everything off (no key in) we disconnected the ground wire to the negative pole and messured with the multimeter the voltage between the negative pole and the ground (some shiny metal on car). It registered about .36 volts (The car would go dead if not driven every day). While I watched the meter, my neighbor pulled first fuse. No change in multimeter reading. Fuse back in, next out. At fuse nr. 5 voltage dropped to .018 volts if I remember right. Thus circuit 5 was somewhere draining. Turned out to be the circuit that turns the head lights out when light switched on. One of the motors had earlier quick working and they had manually set the lamps to be out all the time. But that motor kept on draining...
Hope that helps in your search.