Danjo2

Sorry, TBC, TBC2 and TBC3. I realized just now that there is a TBC4 (you’d think they’d all be adjacent). I didn’t pull TBC4. After collecting my observations, I put all the fuses back and found the BCM. I disconnected all the connectors and tested again. Same. .5A for 60 seconds then to 0A.

I pulled 16, 18 and 19

The BCM

mountainmanjoe

I don't understand why you're pursuing the BCM, if the 2 Amp drain went away when you pulled the TCM fuse.

TCM is the Transmission Control Module.
BCM has its own separate underhood fuse on my van.

EDIT: OK you posted your correction just as I posted this. TBC is the BCM.

mountainmanjoe

So you know that one of the accessories that is controlled by the BCM is causing the drain.

Free diagrams:
BBB Industries- Premium Alternators, Starters, Power Steering Products and Turbochargers | TSB and Wiring Diagrams Database

marksue8@comcast.net

I had the same issue. Turned to be that the light on the Visor stayed on if I had a couple of pages of paperwork in there. Took them out no more draw! Hope it is something simple like this for you
2007 3500 LMM Express Cutaway Parasitic Draw


I have a 2007 Express Cutaway that’s a Thomas Built short bus. I have a parasitic draw that’s draining the battery in a day or two. It’s drawing 2 Amps.
I’ve worked on tracking it down as follows:


Measuring current flow through the engine compartment negative cable while pulling each fuse one at a time starting with the bus body, then the fuse block under the seat,’then the fuse block under the hood. No change.


I disconnected the fusible link on the under hood block. No change.


I disconnected the primary wire from the under seat fuse block. No change.


I traced the cable for the wheelchair lift and disconnected it. No change.


Then I decided to work from the positive side. There are several hots connected under the hood. I’ve tentatively identified these as Wheelchair Lift, Bus Body, Cutaway Van Starter/Under Hood Primary/Interior Primary.


I separated each of these, except for the “Cutaway Van” part where the interior/under hood/starter are part of a factory made inseparable cable.


The bus body, no current.


The wheelchair, no current.


The “cutaway van” current.


So focusing on the Cutaway:
Disconnected the primary to the under seat fuse block. No change.


Pull each fuse one at a time and each relay one at a time from the under hood fuse block. No change.
Disconnect one side of the fusible link on the under hood block. No change.


So that’s where I’m at.


Is the alternator fused through the fusible link?


If anyone has ideas for how I can proceed to test further, please let me know!




Thank you!
Danjo[/QUOTE]

Suzanne Simpson

I have a 2011 chevy cutaway and the exact same thing is happening. Did the same tests as and have found nothing! Were you ever able to find the cause?;