Red wire under passenger seat - fuse?

[Montecha]

I'll need to have my 2nd Battery under the drivers seat - unless I swap the sub and amp around (as the sub is currently under the passenger side). Is it possible to re-use this factory wiring on the drivers side, or should I ignore the existing 2nd battery wiring.

Also as I'm just looking to power: a parking heater, USBs, roof Leds and a cigarette lighter socket is there a small (physical and Amp/h) zero maintenance unvented battery that folks use?

 

[Bundu]

Hello fellow Sixers

I've been researching installing a second battery under the front passenger seat. Yesterday, I took the seat out and found this:


A collection of seven +12VDC wires just strung up going nowhere. They are bound in 2 bundles, 4 and 3:


They appear to be permanently live. I know I have seen this in a thread somewhere, but for the life of me can't find it now.

• Does anyone know where they terminate?
• What sort of current can they support?
• Is this the plumbing used for the factory leisure battery?

Any help in answering these questions is greatly appreciated!

 

[Skyliner33]

I have similar, but mine are not all the same thickness.



The bundle of 3 end like this:

 

[Pauly]

Looks like the redundant factory underseat feed (as you don’t have the additional fusebox) then it’s been joined onto for your towbar (the three fuses in the holder)
Have you got one cable much fatter than the rest, I did and it’s a 50a feed direct from the e box under the battery, I used it to feed my dc dc charger and fed the towbar wiring off my leisure batt (I don’t tow only use a bike rack so modified the wiring)

 

[Skyliner33]

Looks like the redundant factory underseat feed (as you don’t have the additional fusebox) then it’s been joined onto for your towbar (the three fuses in the holder)
Have you got one cable much fatter than the rest, I did and it’s a 50a feed direct from the e box under the battery, I used it to feed my dc dc charger and fed the towbar wiring off my leisure batt (I don’t tow only use a bike rack so modified the wiring)

Yes, I do have one much fatter. I didn't use it for the dc-dc feed for 2 reasons. If the fuse blows its in an awkward place to get to and I put mine under the drivers seat.

Also @Pauly I'm having trouble with my Kombi step light, when I plug it in to the OEM courtesy lights using the loom it stops the courtesy lights timing out after about 15 mins. They don't time out but work properly with unlocking locking ignition etc.
Any suggestions please? I've sent a pm as well.

 

[Bundu]

Thanks

I'm just wondering if 1 wire in the bundle is supplying and the others feed somewhere else or are they all feeds from the main fuse box.

Don't unnecessarily want to cut the link.

 

[Nickdaw]

Hi I hope some one can help. I was fitting a b2b charger under the passenger seat and was going to use the red wire that’s about 6mm that seems to connect to a couple of smaller red wires. And wile trying to work it out it touched earth and I heard a fuse or something similar, I have tried to find which one it could be but can’t. Everything seems to work on the van but now there isn’t any power from that red wire. Any help please

 

[rod_vw]

Have you looked in the 'E' box under the battery?

Take battery out, remove steel tray that it sits on, remove big plastic cover first having removed the plastic 'key' that holds the little fuse holder by the slam panel in place and allows it to drop clear of the big cover as you lift that off. T20 (I think) Torx driver required to remove the screws that hold the plastic cover.
That's where fuse block SA is located.
If you need a large cross section cable for your leisure battery supply it should be connected at SA3 position, a large bolted down fuse, 50Amp or 100Amp depending on use.

Wiring diagrams and workshop manual here - https://cardiagn.com/volkswagen/volkswagen-transporter/

 

[Nickdaw]

Thank you. All fixed now, I had a bit of a panic in case something wouldn’t work.

 

[Epic-Rob]

OK on my 2016 T6 I have a 6mm cable that comes out under the drivers seat and has a couple of thinner wires off it going to fuses under drivers seat (all those fuses ok) I am guessing from posts that this is the wire for an auxiliary battery.
its a perm live when engine running so i have used this to power the split charge relay, but i think i have blown the fuse in it as in is no longer live. (yes yes i KNOW i should have disconnected van battery....)
I have trawled threads and wiring diagrams but cant figure it - thought it would be easier to ask rather than pull every fuse in van....

Update - on a bit more forum searching and on one of Dellmasive how its done threads it would appear that this fuse is #3 located under the battery - can someone smarter than me 2nd that

 

[Loz]

Yes in the e-box and it’s a permanent live.

 

[Deaky]

The fuse is in the Ebox.

https://www.t6forum.com/threads/guide-battery-removal-fusebox-sa-e-box-access.25042/

the one you want is in slot 3, the empty one pictured in the guide above

 

[Epic-Rob]

Thanks, i did start to take that pannel off before thinking 'there is no way its in here'..... and put it back

 

[rod_vw]

Thanks, i did start to take that panel off before thinking 'there is no way its in here'..... and put it back

Ah, it's hidden from 'playing fingers', as are all the other things in there.

And not least a pain in the a** to get to.

 

[Epic-Rob]

Well i found a blown fuse but it was a 50amp in slot 8!
havent put new one in yet but i am guessing this is the one.

 

[marcbrandon]

As Epic-Rob just described above...I also backtracked the thickest red wire (approx. 10mm2) below the passenger seat, to cable number 8 in the E-box and it already had a fuse installed but of 100A instead of the 50A described above. I'm a bit confused why VW placed such a high value fuse for such a thin (10mm2) and long cable (from E-box to driver seat)..??

 

[vollodymyr]

Hi, Could you please help me with identification of the fat red wire (blue circle )located under the driver's seat. Is it the one marked on the scheme?

 

[rod_vw]

Hi, Could you please help me with identification of the fat red wire (blue circle )located under the driver's seat. Is it the one marked on the scheme?View attachment 277770View attachment 277769

I'll start with the assumption that you have a vehicle with a factory fitted second battery, if you don't that wire will not exist.

Now lateral thinking..

Trace the wire, if it goes to relay J7 Terminal 2 then you are correct.
If you can't be sure that you have found J7 then confirm that it is live now. Access the fuse box that is under the engine battery in the E Box and remove Fuse SA3. If the wire is now dead again you are correct. Long winded method but 100% accurate.

 

[vollodymyr]

I'll start with the assumption that you have a vehicle with a factory fitted second battery, if you don't that wire will not exist.

Now lateral thinking..

Trace the wire, if it goes to relay J7 Terminal 2 then you are correct.
If you can't be sure that you have found J7 then confirm that it is live now. Access the fuse box that is under the engine battery in the E Box and remove Fuse SA3. If the wire is now dead again you are correct. Long winded method but 100% accurate.

Thanks for the reply and the tips. I don't have either the second battery or the relay installed yet. I am trying to determine if that's a factory-installed wire that I can use to feed the second battery. I find it strange that the big wire is just taped together with two other wires feeding two 15-amp fuses, which I am struggling to locate on the schematics.

 

[rod_vw]

Thanks for the reply and the tips. I don't have either the second battery or the relay installed yet. I am trying to determine if that's a factory-installed wire that I can use to feed the second battery. I find it strange that the big wire is just taped together with two other wires feeding two 15-amp fuses, which I am struggling to locate on the schematics.

If you don't have a vehicle that left the factory with a second battery it's very unlikely that the wire is installed. Proof will be to look at the FA fuse block in the E box for fuse position 3, if there is a red cable on that location then that should be it but I doubt it's there.
If you are installing any type of additional battery then this is the ideal location to connect up to the existing +ve 12v vehicle system obviously with the appropriate fuse installed. With a vehicle having a smart alternator and Stop Start Technology it's best to fit a Battery to Battery unit not a simple relay as VW still fit, where you site this and which make you use is up to you. Many of us are using Victron kit but there are others out there.