Parasitic Battery Drain

[pebs]

My 2016 VW Caddy Maxi (ex BG fleet) has been experiencing a battery drain for a while now but its getting worse. It is not a constant drain and when I put my voltmere in series (measuring live current) its in the single digit mA reading and within the normal range. I've bought a bluetooth voltage tracker and recorded the battery isolated and when connected to the van.

Pictures are linked

https://ibb.co/r2vnWfp
https://ibb.co/72drJx0

Pic 1 is a side by side comparion of the voltage over a 24 hour period, with the left trend when the battery was disconnected (showing the battery can hold charge). The right trend is after i reconnected the battery to the car and took it for a drive hence the higher voltage.
Pic 2 is a zoom in on the following night where I left the battery is still connected giving a better view of the repeated voltage spikes

I believe the data is recording every two minutes but its clear there is something periodically draining the battery. I know I need to get the voltmeter out again and wait long enough to measure the spike in current i'd expect to see from the drop in voltage.

Any ideas on what it could be?

I've removed all my aftermarket electronics but since this was a fleet vehicle its possible there are others still installed im not aware of. I suppose I'm wondering if the pattern of voltage drain rings an alarm bells for what might be the culprit?

[Doc]

Welcome to the forum.
BG had quite a bit of electronics added to their Caddys, they had an extra fuse panel added to distribute to the extra items.
You will likely find something on their extra fuse panel which is charging or transmitting or similar.

[pebs]

Do you know where this extra fuse panel is likely to be located or what it looks like? As I have not been able to find anything

Also doing some further testing with my voltmeter, the current spikes to 1.5A for 30 seconds ever 6 minutes routinely, using up about 4Ah per day which is the source of my drain. I will be going through the fuses 1 by 1 but does this ring any alarm bells for something?

[Doc]

On the Caddy4 I think the extra fuses are under the dash top centre cubby.

[Sabbunsingh]

On the Caddy4 I think the extra fuses are under the dash top centre cubby.

Not on any caddy 4 I have seen.

Sent from my SM-S911B using Tapatalk

[Doc]

Fair enough, I've not worked on an ex-BG Caddy4 so I'm going off what I've read. I'm open to corrections as always.

[Sabbunsingh]

Tbf I have only worked on 2 bg mk4 and it was to fit them aux gauges in the dash tray. I could also be wrong

Sent from my SM-S911B using Tapatalk

[pebs]

The van has a fuse box in the bonnet and a drivers fuse box but having pulled all the fuses out there is no difference.

However I have made some progress and these are the facts"

Nominal current when locked = 0.06A
Nominal current when unlocked = 0.14A

When locked, every 6 minutes the current spikes to ~ 1.8As for 15 seconds, then ~ 1.4A for 15 seconds, then back down to 0.06A

When the van is unlocked and I open any door, current spikes to 1.8A in the same pattern described above (although drops down to 0.14A as is unlocked

This makes me think a module ( body control module?) Is waking up every 6 minutes. I'm interested to know what turns on when this module wakens, but I suspected the radio so I unplugged it and repeated the test.

Every 6 minutes the current spikes to 0.6A for around 10/15 seconds. This is the same trend previously but at a lower current for shorter period. This makes me thing the module is waking the radio, which then stays on for longer even after the bcm shuts down. The difference between the spike at ~1.8A for the first 15 seconds and ~1.4A for the second 15 seconds is a drop approximately equivalent to the 0.6A I'm reading when the radio is disconnected, suggesting the bcm is turning off but the radio is staying on.

Does this sound plausible? I'm not very familiar with control modules and what steps would you suggest next?

Interestingly in the drivers dash there is some metal that is rusted/oxidised (picture attached).

https://ibb.co/2hQ9Fx1

I believe this is a similar location to where bcm (or other modules). Potentially related if there is water damage? Although water damage would be a less consistent current spike than the every 6 minutes I'm getting currently.

[nickrsp]

I have exactly same problem on ex BG 2016 caddy maxi . Narrowed down to radio possibly but got no further . Currently isolating battery when not in use pending further testing. Did you get any further ?

[Larryd]

Add me to this list, BG van with a parasitic drain.

I have a whole day to go balls deep into this with a multimeter, I'll let you know what I find.

[maxx007at]

It could well be your CAN gateway keeping some modules awake, it sits above your BCM.

On your rusted dashboard metal, I do also see a blue cable, is that an ground for something?

[Larryd]

Ok, balls deep is what I promised, and I've just put the tip in.

Parasitic draw on my van is 1.38 amps after a half an hour shutdown

First thing I tried, headunit.
The drop was severe, 1.38a down to 0.2, which is still too high, but progress.

This van is new to me, and I don't have a lot of experience with VW, I've had multiple BMWs over the last 12 years.

Looking at the supplied photos, can anyone spot why this headunit would be pulling that current when the van is supposed to be sleeping?

[Larryd]

Next one....

This cable on a fuse adaptor pulls 0.07 of an amp.
No idea what it is for yet, I'm just finding the faults.

[Larryd]

And couldn't find anymore

Been through the engine bay box, the driver's side box, and went looking for a 3rd been as though it's a gas van, but this was empty

[Nicklouse]

Ok. Photo of the connectors on the front of the engine bay fuse box. Will highlight if there is an extra power takeoff. Have looked behind the glove box area? It is an agree that is often used to pass cabling through from the engine bay. And was also where the MK3 BG vans had the extra fuse box and PCB. For the different required voltages.