Retrofitted webasto wiring

[rhyre]

Hey, I've just installed webasto vevo to caddy 2k5
Everything works except for starting fans without ignition. I got manual AC and i've read i need to get webasto pin8 wire and connect it to something. And there is a problem. I dont know where to. Anyone got some pictures and diagrams where connect it to? Some say J13 relay but internet search came with nothing which one is it.

[petrev]

Hi,

Not all Webasto/VW have the fan signal output on pin8 connected!

Mine didn't - Have to connect the water pump power to a relay to switch on power to the heater fan when the Webasto is running.

My notes on my particular install
https://caddy2k.com/forum/viewtopic.php?p=447471

[rhyre]

You are not authorised to read this forum.

My plug doesnt have wire but i got new plug with all the wires. VCDS got some V2 Blower on/off indicator.
So you just basically have to connect power through a relay to pin3 of this 10pin plug on fan ? And thats it?

[petrev]

The official VW method is to cut into the speed-2 output wire from the HVAC panel and insert the changeover relay to swap to a constant feed.
This means when you power up your Webasto you automatically get speed 2 whatever the control panel is set to.

[rhyre]

Ah thanks now I get it with changeover relay. In diagrams it was a connection and I didn't understand how it supposed to work

[TDI_P0w3r]

Hello friends,
Happy 2026 all the best!
we have one target for this retrofit can you provide details what exactly Webasto did you use and what another is needed for a mount of the entire system.
Thanks

[petrev]

Personally I used an Arteon unit from eBay.de

There are a lot of bits you need ...
Not least
Mount
Screen Wash water bottle
Fuel pump
Fuel pipe
Exhaust pipe
Water pipes and valves
Wiring loom (bespoke)
Fuses and switches
Water pump (?)

Full list in a post that you can't get to, sorry.

[rhyre]

be sure to get those metal water pipes that go behind engine