Vampiric Draw on my 2014 PPV

[Odii]

I'm looking to get some thoughts/insight as I'm getting pretty stumped.

I have vampiric draw on my 2014 tahoe ppv, sitting at .19A even after everything has shut down (lights off etc). testing this by inlining my meter on my neg battery terminal, and letting it sit for ~30m or so to ensure everything has settled down.

to try and eliminate *stuff* i went down to just a single battery, and disconnected all the extra accessory hot wires.

I removed all fuses I could find under hood and under dash (clicked door so it thinks it is closed) but not a single fuse made the draw budge.

it *appears* if i disconnect the alternator i can get it down to .03


is it possible and/or how likely that my alternator is bad? broken diode?

I'm currently working on this thing in the street, and it has mostly been cold/rainy - so while i don't mind being cold and wet, it is certainly less than ideal circumstances to try and work on something above my skill level. I'm hoping some crowd-thinking might help me out.

 

[iamdub]

I'm looking to get some thoughts/insight as I'm getting pretty stumped.

I have vampiric draw on my 2014 tahoe ppv, sitting at .19A even after everything has shut down (lights off etc). testing this by inlining my meter on my neg battery terminal, and letting it sit for ~30m or so to ensure everything has settled down.

to try and eliminate *stuff* i went down to just a single battery, and disconnected all the extra accessory hot wires.

I removed all fuses I could find under hood and under dash (clicked door so it thinks it is closed) but not a single fuse made the draw budge.

it *appears* if i disconnect the alternator i can get it down to .03
View attachment 390013

is it possible and/or how likely that my alternator is bad? broken diode?

I'm currently working on this thing in the street, and it has mostly been cold/rainy - so while i don't mind being cold and wet, it is certainly less than ideal circumstances to try and work on something above my skill level. I'm hoping some crowd-thinking might help me out.

What did you disconnect on the alt- the charge cable (battery positive) or the PCM control (small plug)?

It's entirely possible you have something drawing power in the alt. I wanna say I've read of this before on this very forum.

 

[Odii]

What did you disconnect on the alt- the charge cable (battery positive) or the PCM control (small plug)?

It's entirely possible you have something drawing power in the alt. I wanna say I've read of this before on this very forum.

i'd need to double check tomorrow, cause now i'm second guessing, but iirc it was the battery-positive side.

I did read on these boards something about an alternator going bad and having it occur, but it sounded like a pretty uncommon thing - and I didn't want to chase it if there was something obvious that my lack of experience is prohibiting me from seeing

 

[iamdub]

i'd need to double check tomorrow, cause now i'm second guessing, but iirc it was the battery-positive side.

I did read on these boards something about an alternator going bad and having it occur, but it sounded like a pretty uncommon thing - and I didn't want to chase it if there was something obvious that my lack of experience is prohibiting me from seeing

I'd have to agree that this particular failure in the alt or its regulator isn't very common. But, it sounds like you've done your due diligence in tracking it down. The PCM controls the regulator so it could be keeping something energized, but not if you pulled the PCM fuse or anything related to the charging system. If disconnecting the main charge cable stops the parasitic draw, then you certainly have a problem cuz it shouldn't complete any circuits between it and the battery (hence, a "short").

Hey, if you've isolated the fault to the alternator, you should be excited that it's such an easy repair versus tracing oodles of wiring and testing other components.

 

[Odii]

hrm, no luck so far.

I think what i need to do is trace both batteries, and all the connections coming off it it and see where they are going and compare that to where they should be going.

It currently has the dual battery setup, and I'm curious if something isn't quite right with that, but i can't see underneat (and im working in the street atm, not even a garage, let alone on a lift). I have a couple of ramps, I should see if that gives me enough room or not.

Once i figure that out, i'll setup the stinger so the aux battery only engages on ignition/key

 

[Odii]

Follow-up:

I did a few things at the same time so I'm not 100% sure which was the fix

but I did replace the Alternator and I took out the RAP ground bolt and cleaned up around it - it is likely this was the cause as accesorries unable to shut down properly due to a funky ground can cause this issue