Charge ignition battery trough the IS1 electrical interface of a T6 van


New Member
Hi all,
I have a waeco UI252A battery charger. It can charge 2 leisure batterys and the ignition battery.
The last one with a current of 1 A.
Can someone tell me if it's possible to connect the wire for charging the ignitionbattery to the IS1 electrical interface. Maybe by the pin a5 of the grey plug?
Any help is much appreciated.
I’ll look at the drawing for you in the morning
Check to see if you have fuse SH30 (40a) Fuse box SH30 is under the passenger seat(RHD) and this is a permanent live that is then present on pin 4 of the grey 6 pin plug under the driver's seat. wire colour red/yellow.
All the rest seem to be switched.
I assume you have you tested for live on that plug and your suggestion is live?
Hello Loz,
Thank you for the quick reaction.
I can't verify at this moment if the fuse SH30 is present, because I'm wayting for my ordered new T6 DSG 4motion. I hope it will be delivered at the end of March.
Now I have a T5 without interface IS1.
I found the description of the pins in the "Body-builder-guidelines-Transporter-EN-45-2017.pdf" - Page 77 is uploaded in attachment.
There I see that connection to the ignition battery is restricted by pin A4. It seems it may only be used to draw current.
At pin A5 (black/red) I suppose that we can supply 2,5 A. As described use: "Ignition bypass terminal 75 (X contact) upholding".
I don't understand very good what this means. Can you explain this a little further? Should supplying 1A at this pin charge/maintain the ignition battery? I'm asking myself what can be the reason to supply a current there?
Kind regards


  • P 77 of Body-builder-guidelines-Transporter-EN-45-2017.pdf
    61.4 KB · Views: 9
The simplest way is to meter all the pins and find one that is always live and still live 20 minutes after removing the key.