RAC - wiring and aux battery!

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smithson15

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Hi all, new to the group and my ex-RAC T6!

I've taken out lots of the wiring out the back and the Junction box from under the passenger seat. Was expecting to be able to take out the extra battery too, but after seeing it feeds some of the VW loom and after a little bit of reading on here it seems that it's an aux battery that needs stay!

So - I guess that under the seat means I can't fit a swivel base there?

Also, does anyone know what the aux battery is feeding? I can attach a wiring diagram and it has numbers, but no description as to what it's doing. Any help would be great. I can't anything for the aux battery in the manual.

Thanks!

Charlie
#teamorange
 

Attachments

  • RAC T6 TRANSPORTER.pdf
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A couple of pictures may help?

For specialist vehicles it's a common pattern to order the base van from VW with the second battery (and charging system) installed at build time. The specialist electrics are then connected to that.

So the RAC diagram only shows the additional electrical system, for the factory fit elements you'll need to view the VW diagrams in the VIP section.


With the factory fit a couple of the underseat feeds move, usually some of the 12v sockets and, if fitted, one of the trailer power feeds, as it's sensible that those are powered from it to protect the starter.

What are your plans for the van?

The battery doesn't need to stay, anything it feeds can be moved to the single battery position, but if the factory install is there you may as well make use of it. If it's the original battery it may need a new one as it's probably been worked hard. If you want to make serious use of a leisure battery now would be an ideal time to consider converting to LiFePo as it will be considerably better and you have the van in bits.

You can still fit a swivel usually, you just need to look for one that is slightly higher to give the battery clearance. Do you have the single or double seat?
 
Legend, Thanks mate. It’s a double seat. I do want a leisure battery but to be honest I’m just thinking of putting the factor my stuff as it was, now that I know how it works, and have a completely separate battery and install for the new stuff going in.
 
Going through the same with our new 2018 ex-RAC T6 as we speak, have you had any more thoughts on your next steps with electrics and swivel seat?

I’m also thinking of getting a swivel seat, but maintaining current battery position under passenger seat if possible.

Will be doing some research today so will post any useful links I find!
 
Thanks mate. Not got that far yet so that would be great. There’s a chance you remove all of your RAC stuff and the battery was added by them so you can get rid. Just so happened mine had an aux battery factory fitted with looms and fuses that I want to leave alone.
 
Hi my son has removed the auxiliary battery but now the engine fan won’t turn off when the engine is on. Can you someone please give us some advice thank you
 
Yeah I’d try and put it all back as it was if you can. If the aux battery is factory fitted then it’s doing other stuff too. When I removed all the fuses for mine there were faults on the stop/start and other issues
 
Curious how you guys are getting on with this, I’ve been stripping all the old RAC stuff this week.Think I’ve done an alright job as van still starts

Been trying to go quite deep into working out what’s what so have taken out seats and carpet. Although despite this I haven’t found a split charge relay between the starter and Auxillary battery as of yet so a little confused! Also no note of one on the RAC wiring diagram.

Making me think that I’ll install my electrics completely separate to the systems in as existing.IMG_4149.jpeg
 
BillyBobHyx said:
Curious how you guys are getting on with this, I’ve been stripping all the old RAC stuff this week.Think I’ve done an alright job as van still starts

Been trying to go quite deep into working out what’s what so have taken out seats and carpet. Although despite this I haven’t found a split charge relay between the starter and Auxillary battery as of yet so a little confused! Also no note of one on the RAC wiring diagram.

Making me think that I’ll install my electrics completely separate to the systems in as existing.View attachment 250630
Click to expand...
Scrap that, I think I understand now, the split charge isn’t on the RAC diagram because it was installed by VW.

Think it’s the ‘100’ in this photo
IMG_4165.jpeg
 
Yeah looks like you have a factory fitted aux battery with some extra looms the same as mine. I just removed all of the extra RAC stuff including the stuff that goes forwards and will install my leisure stuff completely separate, and leave all that alone. Whilst you’ve got it like that might be worth running your battery pos from the starter battery to wherever you’re putting a leisure battery. And I also ran a couple of speaker cables from the head unit into the back for future fit.

If you remove all the RAC loom you’ll lose your power to rear view camera. So I just took a pos and a neg to the screen from under the passenger seat and a trigger wire from reverse light too. But your pos needs to be live when the ignition is on, if you take it direct from that battery it will be live all the time even when the van is off. There's a little yellow cable on a purple plug under the seat that I used, not sure what it was doing on the RAC stuff but I’ve used it.
 
That little yellow cable on the purple plug can you see what that is labelled up as? On the copex? Would be good to know what it was doing.
 
Butch1976 said:
Hi my son has removed the auxiliary battery but now the engine fan won’t turn off when the engine is on. Can you someone please give us some advice thank you
Click to expand...
Could just be a DPF regen?

Has it done it again?
 
Hi, new to the group and have a 2018 ex RAC that I’m trying to sort the wiring like above to put in a swivel double seat! I’m relocating the new leisure battery and was wondering if the 10mm red cable going into the 100 relay is direct to the battery or somewhere else. Thanks
 
If you have a T6 with the fuse/relay board as pictured then you likely have factory fit and then yes the 100 relay is your split charge relay, the T6.1 uses a larger discrete relay with bolted cables.

Generally it would be fused at 80A at the auxiliary battery via a small battery mounted fuse box, and fed from a 100A fuse in the "ebox" under the starter battery - try very hard not to blow the 100A fuse as getting to that box is a royal pain, they're very much "last ditch" fuses.
 
Could I disconnect the red wire between the main battery and the 100 relay(factory split charge) and connect my own split charge to a new leisure battery?
 
I'm not sure why you would want to replace the factory split charge relay?

If you mean you want to replace the rather simplistic relay with a DC-DC charger to get better charging then yes you can use the feed from the starter battery to feed such a charger, and you should use the switching wire that turns the relay on as your ignition on signal to the DC-DC charger. That's quite a common upgrade a split charging on smart alternator systems isn't a great idea.
 
Lovely, yes my intention is to replace to relay with a dc-dc but wanted to make sure that the big red wire was direct to the starter battery and not on the alternator or something else!
 
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