Mystery towbar cable

[minieggs]

Hello,

I'm just organising the rats nest under the passenger seat ready to fit my own aux battery etc. under the driver's seat.

I've removed the battery that came with the van, and have managed to work out 95% of the wiring, but there's one which has me flummoxed.

It's a feed that came directly off the 12v positive terminal and splits into two. One goes to a mini fuse-board (just to the right of my thumb which I guess is the for towbar), and the other goes via a 30a fuse to the towbar relay (643).

I don't know anything about towbars as I've never had a need for one, but I presumed it wouldn't need a permanent feed, just an ignition feed, but I guess that's wrong.

What is the wire for, and what should I do with it? Should I just re-add it into my new auxiliary battery?

Cheers!

 

[Deaky]

Do you have an ex RAC van, if so the wiring may be different to normal. There is a diagram here EX RAC wiring diagrams

 

[jayc001]

13pin socket or 12n&s requires 1 x permanent feed and 1 x engine running feed so seems normal to me.

 

[minieggs]

Do you have an ex RAC van, if so the wiring may be different to normal. There is a diagram here EX RAC wiring diagrams

Thanks for the link. It appears to be factory wiring and I've ripped out all the RAC stuff.

13pin socket or 12n&s requires 1 x permanent feed and 1 x engine running feed so seems normal to me.

Great @jayc001 - I wasn't sure if it needed a permanent feed, so I'll just re-attach it to my aux battery.

 

[rod_vw]

Err shouldn't a tow bar have a module that controls its circuits and in turn is controlled by can-bus from the BCM? It also switches off rear parking sensors, vehicle fog light etc. via can-bus. In my experience that module is much larger than the relay plugged into that mounting frame.

 

[minieggs]

Err shouldn't a tow bar have a module that controls its circuits and in turn is controlled by can-bus from the BCM? It also switches off rear parking sensors, vehicle fog light etc. via can-bus. In my experience that module is much larger than the relay plugged into that mounting frame.

There is also a module under the driver's seat (I don't have a picture but it looks like the image below). I've not pulled up all the floor mat (as I'm parked on a massive hill and don't want to mess with the handbrake!) but it looks like the wires go from the relay above, through the loom, and towards the module under the driver's seat.

 

[n10n]

The relay should control ignition live of the towbar socket.

At least in 2018 OEM towbar it goes like this:

30A Fuse -> relay -> brown connector in left seat base -> connector in left D pillar -> towbar socket pin 10

 

[rod_vw]

There is also a module under the driver's seat (I don't have a picture but it looks like the image below). I've not pulled up all the floor mat (as I'm parked on a massive hill and don't want to mess with the handbrake!) but it looks like the wires go from the relay above, through the loom, and towards the module under the driver's seat.

View attachment 200157

Yes that is the trailer control module.