Something is Drawing Power When the Car is Off

[BBShark]

I have a blade style battery cutoff switch (like the electric chair) on the negative terminal. With the car off, ignition switch off and battery cutoff, I am reading .15-.25 volts. When I look at the current between the chassis ground and the negative terminal, I see 0ma.

Does this make sense?

 

[phantomjock]

Sounds like you have a Ground Loop.
Something is finding a path to ground - other than the primary. I bet if you cut the + with the blade it will go to Zero.
A hot-wired safety switch (roll-over fuel cut-off). or security system , maybe. Time to start pulling fuses and chase electrons.
Best of luck.

Cheers - Jim