I had to replace my heater fan motor. Since May, the dash is out,
and I managed to rip out everything down to the bare metal. usebox, 
heaterbox, wiring...
My dedicated goal was to update the wiring.

I develop automotive wiring for a living, so I had many little helpers 
at hand. Like zip ties, edge biter, clips, various tapes.
Also a P-Touch label printer.

My advice:
-Proper fusing at the beginning of the wiring only
-Although it´s cheaper for the OEMs, do not splice. Use connectors. On 
three-wire joints, doublecrimp only to create a Y-shape with two 
connectors. Our Vanagons use this style on several switched 12V near the 
fusebox.
-Tape/Tube branches by theme: Wiper, locking, windows...all in separate 
bundles. You can always zip-tie if they take the same route under the dash.
-Figure out a strategy upfront, before missing one electrical gizmo: 
Don´t cheat by splicing again!
-Put in a few spare fuses and supply branches for future use.

I raid junkyards for compatible connector systems:
Fuses that slide/clip onto existing fusebox.
I have 500 terminals of the same type, as male/female for different wire 
sizes (usually 4.8 and 2.8mm flat blades). I always stay with them. 
OEM-used on nearly every VW/Audi since 1990.
Use bare terminals and a VW/Audi connector housing. Don´t use the 
red/yellow/blue insulated terminals. Cheap crap!

Don´t hope for clean optics behind the fuse box. No matter how 
well-prepared you start, it will be a horrifying mess after ca 50% of 
whole install.

Fixing/routing:
OEM routed the branches underneath the brake booster, heaterbox, from 
left to right A-pillar.
The branches can be nicely zip tied to the heater box itself. There are 
thin plastic walls on the box, right above the metal brackets that 
secure the box to the lower cross-car beam.
I put edge biter clips on these plastic walls, which hold the wiring 
bundle via a zip tie.

Alternative routing:
I also found holes on the upper X-car beam, right underneath the 
windshield. You can´t see them, but feel them on the underside. 4-6 
holes, left to right, for firtree-ziup ties.
I was thinking about routing my wire bundles there, but didn´t. Once 
they are in there, and the dashboard installed, you will never see them 
again! I have retrofitted, like, 749 extra modules and gizmos, so I know 
I ned to keep my wire buindles accessible.

I have a lot of photos of all this, but I could only offer them 
oncummented in a ZIP.
No webpage created yet!
Examples (I am using a mix of Golf/Eurovan fusebox):
www.v6bus.de/ZE.jpg
www.v6bus.de/zehiu.jpg
www.v6bus.de/zehio.jpg
www.v6bus.de/ziptie.jpg
www.v6bus.de/ziptie2.jpg

Regards
Raimund
*phew, done typing*

Am 24.10.2021 um 01:46 schrieb Richard Koerner:
> My van is 85 tintop.  Second owner, since 1989.  So I am the DPO.  I've added electronic accessories along the way:  Honda Radio, Audiovox Cruise Control, Garmin GPS, even a switch to activate valve on my hot water/shower setup, hidden fuel pump kill switch.  All works Great!.....until it doesn't, like on latest cross country trip the radio just stopped working while driving along.  Okay....I made the bonehead mistake of "kludging" the connections, kept hop-scotching.  There are primarily three:  Ground, Constant 12VDC, Switched 12VDC.  I just kept splicing into existing things.  I need a better way.....it is definitely looking like an Octopus out of control under there.  I have some ideas in mind, but thought I would ask the gang if they have any tips.  Also....it would be super helpful to have wires of different colors, like they do at the factory; I'm sure I could find at FLAPS, Amazon, or Ebay but maybe you know good source.  My basic plan is to use generous lengths of wire, zipties, and appropriate labeling.  Systematically clean things up.