Ignition Live Under Passenger Seat - How Its Done -
- Thread starter Dellmassive
- Start date
The 2.5mm² red/yellow at pin 17 (red connector) is permanent 12V. Actually it is only 1.5mm² on "van side" from fuse SC46 to the connector.
The simplest way is to take feed from leisure battery to above mentioned pin 17 (or tap into existing red/yellow and remove SC46). Hopefully the attachment clarifies.
EDIT: For the coding change see --> Webasto Auxiliary Heater - customizing
Hello all, thanks for this awesome write-up @Dellmassive and the other helpful contributions.
Please could I have some clarification on a couple of points?
Please could I have some clarification on a couple of points?
- I want a DC-DC charger for my aux battery under the passenger seat of my T6.1 (when it comes) I understand there are 2 options to achieve this
- Take an ACC+ from the fusebox which means I could drain my starter battery if the ignition is on
- Take an ENG-RUN+ from the BCM which means I can't drain my starter battery if the ignition is on
- I prefer opt 2 above but I can't see (it probably is somewhere) the pin number on the BCM connectors and which connector it is (I think there are 2 x 72pin connectors - 1 black and 1 white)
@z1ts - thank you - glad the thread helped.
1 - correct
2 - see below for more info,
www.t6forum.com
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you will need to confirm the pinout id the same for the T6.1 as the T6.
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1 - correct
2 - see below for more info,
Tailgate conversion - BCM Connector pins and numbering system.
Hi All Finally I'm trying to run a wire from my tailgate conversion to the BMC. I've run the wire, removed the BCM and opened the black connector. What I can't see is where pin 23 is in the connector. Does anyone have a diagram showing where the pins are? Thanks in advance
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you will need to confirm the pinout id the same for the T6.1 as the T6.
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So now I'm a VIP member to a forum about a van I don't yet own!!!
Oh the irony!!
(I was committed to do it at some stage as I'm just blown away by how valuable this place is)
Thanks though @Dellmassive your help is much appreciated.
I think it's pin 3 in connector T73a which I believe is the black connector! Time will tell and if there's anyone who knows definitively then perhaps they could drop their pearls of wisdom here!
Oh the irony!!
(I was committed to do it at some stage as I'm just blown away by how valuable this place is)
Thanks though @Dellmassive your help is much appreciated.
I think it's pin 3 in connector T73a which I believe is the black connector! Time will tell and if there's anyone who knows definitively then perhaps they could drop their pearls of wisdom here!
IMHO and as said on a few occasions in the thread, getting to the BCM and tapping the right pin is a bit of a nightmare and a lot of effort although it is the 'right' technical solution. But if you manage to leave your ignition on the DC-DC is not going to be the only thing draining your battery and maybe not the most pressing problem.
I would offer a couple of good reasons to tap off the fusebox. 1. Its easy to remove if you change your DC-DC in the future. 2. Its easy to check the sensing fuse. 3. You won't have trouble with ALL of the rest of the serviecs if you mess up the BCM connector.
I would offer a couple of good reasons to tap off the fusebox. 1. Its easy to remove if you change your DC-DC in the future. 2. Its easy to check the sensing fuse. 3. You won't have trouble with ALL of the rest of the serviecs if you mess up the BCM connector.
I would offer a couple of good reasons to tap off the fusebox. 1. Its easy to remove if you change your DC-DC in the future. 2. Its easy to check the sensing fuse. 3. You won't have trouble with ALL of the rest of the serviecs if you mess up the BCM connector.
Good reasons, one more:
4. Engine run signal needs to be enabled by BCM coding if wire is retrofitted. Not a big deal but requires access to VCDS, OBDeleven or equivalent tool.
Thanks, some sound words of wisdom there. CheersIMHO and as said on a few occasions in the thread, getting to the BCM and tapping the right pin is a bit of a nightmare and a lot of effort although it is the 'right' technical solution. But if you manage to leave your ignition on the DC-DC is not going to be the only thing draining your battery and maybe not the most pressing problem.
I would offer a couple of good reasons to tap off the fusebox. 1. Its easy to remove if you change your DC-DC in the future. 2. Its easy to check the sensing fuse. 3. You won't have trouble with ALL of the rest of the serviecs if you mess up the BCM connector.
I am a proud owner of a VCDS Hex something or another having 10 VAG vehicles on the fleet I manage as part of my day job
so not a huge issue for me, but a stumbling block for quite a few.
It is pin 3 in the black connector on the BCM. Full wiring diagrams are here T6 - Aux Battery (non camper) Wiring Diagram
And boom! Just like that, confirmed!
EquanimousMike
New Member
First reply on this forum and its on a topic that's been hashed to death.
I feel like I followed these instructions to a T and used the black wire to trigger my DC-DC charger.... All seemed good but then I turned the van off and the charger kept charging.
I checked the black wire and sure enough 12v still active. I must admit I panicked and disconnected the system.
Is there any chance this wire stays live for a while after the engine is off? Wouldn't have thought so.
EquanimousMike
New Member
And upon further inspection it appears that pin 3 on the BCM is +12v when the ignition is off? Whaaat?
Someone help me figure out where i'm going so wrong.
I'm working on a T6.1 Transporter with second battery. IS2 if option codes mean anything to anyone.
EDIT: Have I been using old information? Just found the updated wiring diagram post 2019. T6.1 - Second Battery Wiring Diagram
Is the battery now being isolated during a +12v signal? That's a pain. What are my options?
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Did you code it? 09 central electrics, long coding, byte 17, bit 4.
This is for T6 though, might or might not be same for T6.1
EquanimousMike
New Member
I haven't changed any coding. I assume it is active as the second battery and isolation relay came standard. I'm just upgrading to a RedArc DC-DC charger and need the positive signal wire.
It seems the signal is positive when the ignition is off? I'm still investigating but seem to be stumped.
@EquanimousMike post a few pics of the setup.
Especially the OEM split relay....
VW me guy have changed it to a switch ed neg instead of a switched pos.
Post a few pics, get your multimeter out.
Especially the OEM split relay....
VW me guy have changed it to a switch ed neg instead of a switched pos.
Post a few pics, get your multimeter out.
Just checked the link above.
Brown is a perm neg.
Black is the switched pos that fires the relay.
So same as the T6.
BCM j519. T73b/58 switched pos to fire relay when engine running.
Brown is a perm neg.
Black is the switched pos that fires the relay.
So same as the T6.
BCM j519. T73b/58 switched pos to fire relay when engine running.
As @Pauly says....
If it's OEM it's already there....
Just remove the OEM relay and de-pin the relay holder.
Move the 12v pos trigger wire over to the DC-DC charger.
Move to two battery feeds over to the DC-DC charger.
Give the DC-DC charger a NEW ground.... The same gauge cable as the pos feeds.
If it's OEM it's already there....
Just remove the OEM relay and de-pin the relay holder.
Move the 12v pos trigger wire over to the DC-DC charger.
Move to two battery feeds over to the DC-DC charger.
Give the DC-DC charger a NEW ground.... The same gauge cable as the pos feeds.
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