Brown wires in engine compartment one not connected - why

you have had some fun.

browns are normally earths
in the engine bay there is a large brown that goes from the battery neg to the disanotic plug
so i think this is a added wire can you find out where the outher end is.

The 2 large wires that run front to back are
red/white to the fuse box
red/black to the ignition switch

 

if every thing is working i would not worry to much but it would be usefull to find out where it goes even to just disconnect it.

In hindsight with all the work you have done it would of been wourth ripping it all out and fit a new loom.
If it helps my van had been fitted with a wrx engine in the past and the electrics was a nightmare and i wish i had just replaced the lot.
Have some k for not setting fire to it in anger.

 

Take them both off. They're obviously not doing anything and, as above, a brown wire connected to +12 is going to cause confusion - brown is the standard colour for earth/0V.

Take 'em off & sling them - then you've got two less to worry about.

 

Remove the one that is hitched to a 12V supply and leave the other in place taped and labelled at both ends as a possible pull through......just in case you need to run another cable in from front to rear at some time in the future.

 

VW vans do seem to have attracted more than their fair share of idiots over the years, this might have stemmed in the past from the period when they weren't particularly valued so run on a shoestring but on the other hand it still goes on. Slightly off topic but saw a van advertised the other day as having its original 1985 radio complete with USB port....quite remarkable since USBs weren't around in those days let alone fitted to an analogue radio.

 

As a PS of encouragement...you can easily identify original VW wiring by the nice, standard colours they used (including stripeys) and the simple, quality brass crimps on the end (not godawful blue things). Wiring should form part of the loom, all wrapped up nicely. Have a look under the dash, above the fusebox - all the stuff there is what it's supposed to look like.

Anything else can probably go: your van will still run, and it'll thank you for it ...

 

Tractors & vans are very similar

 

Disconnect the one attached to + and see if everything still works? if so tape it up, It may have been used to liven up your 'Crackin stereo'

 

It could be worse i burnt out a military landrover loom once.
I had to change the dash and make it water proof for wading so cut all the wires and soldered on plugs as per the spec switched on and watched it go up in flames.

On a landrover 90 dash there are 3 identical yelllow/black cables 2 are pos and one is neg