im cam, a licenced diagnostic tech.
you will need to determine if you have a draw or not. And how many amps the draw is.
as a general rule, 0.15 amps is about the limit for a draw while .05 amps is optimal
to check this you will need a multi meter with a amp feature.
you will have to disconnect one of the battery terminals and put one lead on the battery terminal that you disconnected and the other on the battery post that it came off of.
than this will give you a amp draw reading.
there will be an intial higher amp draw for anywhere between 10 seconds to 5 minutes while the computer shuts systems down, but it should read no amps within a few minutes.
IF you have a draw, than you will have to locate it.
you do this by pulling fuses untill the amp draw goes to "0".
you then locate a wiring diagram for that fuse and see what is on that fuse circuit and what its powering.