Battery/Alernator issue

Remove the negative cable and put the meter between the cable and negative post and see how much of a draw you have. I don't think it should be over .5 volts. If it is, start removing fuses one at a time until the voltage falls off. If nothing in the fuse box affects it, you'll want to start removing power wires from big under hood stuff like the alternator, starter and flux capacitor. lol