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

 

[BBShark]

This is weird. If i leave the cutoff switch on and leave the car sitting for a day (possibly way less time) and open the switch (negative disconnected), then open a door, the footwell courtesy light flashes and then goes to a state where it is on but very dim. The footwell lights are LEDs.

Now I'm thinking that there is some capacitance in the system somewhere that charges up and discharges when the door is open?

EDIT: I just tested this theory. opened the door, lights flash and immediately dim. Voltage between chassis ground and pos terminal 3.30v. Left the door open for 10 minutes, voltage .50v. Another 10min, voltage is .26v. 10 more, .14v