I am trying to figure out what might be causing this. I have a battery drain and I have isolated the #15 fuse using a 12 volt light test. I have tested and disconnected everything that is listed on the fuse box (interior and door lights, trunk lights, seatbelt handover arm, antenna, vanity mirror lights) and the drain is still occurring. If I take out the fuse, the drain stops. The fuse does not blow and the car starts when jumped. The battery seems to hold power overnight when not hooked up.

What could I be missing here?

Any insight would be appreciated.