New engine bay loom electrical connectors !

After long and frustrating battles with my car (86 gti) im starting to fear that a lot of my troubles lay in the loom itself ! I already know of several wires that are breaking up and need replacing but as its my daily doing this would be a nightmare/breakdown waiting to happen..
I have a bare shell sat here so I was thinking that I could use it to mock up a new loom.
But does anyone know if I can buy all new connectors for this ? Mainly fuse box end im thinking ?
Any help or advice would be amazing !!
Thanks in advance !!!! Jake.

Try the main dealers for some of them, I've just ordered a few to repair my loom. I used this site to get the part numbers for the connectors - http://etka.cc/vw/main_group/markt/RDW/modell/GO/year/1986/hauptgruppen/1234567890/drive_standart/64/lang/e 

engien bay side a lot of them are standard 2.8 or 6.3mm latched spades, some of the 2 pin plugs use std junior/power timer terminals and plugs.

fusebox side they are multimate type 3 and mate-n-lock for the big ones. I get most of my gear from farnel

TE/AMP Junior/Power timer:
927779-1 - female, offset crimp - 0.5-1mm
927768-3 - female - 1-2.5mm (2.1-3.1mm insul.)

TE/AMP multimate type III:
163084-1 - female - 0.75-1mm (2.01 - 2.49 insul.)

TE/AMP Mate-N-Lok:
925661-1 - 0.5-2mm (2.50 - 4.50 insul.)
350390-1 - 2-6mm (2.54-4.57 insul)

TE/AMP spade, 2.8 mm (.110 Series)
160655-2 - female latched - 0.5-1.5mm (2-3.1 insul.)

TE/AMP Spade, 6.3mm (.250 Series)
160526-7 - female latched - 0.5-1.5mm (2.3-3.3 insul.)
160447-5 - female latched - 1-2.5mm (3.5 insul.)
180384-2 - female latched - 3.0-6.0mm (3.43-5.08 insul.)

293041-2 - male latched - 0.3-1mm
42241-2 - male latched - 0.80-2.00mm
60701-1 - male latched - 2-6mm

if you needed to redo the battery live cable its a 9.53mm spade fusebox end:
280755-4 - female latched - 6-10mm (5-7 insul.)
280756-4 - female latched - 3-6mm (3.4-5.1 insul.)

battery end is 6mm ring, a real struggle to get those large enough, I had to get mine from digi key:
626037-2 - 4-6mm (3.2-5.3 insul.)

smaller 6mm rings are no problem from farnel for the earths to the head and such:
60700-2 - 0.5-1.4mm (2-5 insul)
60625-1 - 0.8-2mm (2.54-3.56 insul.)
626034-2 - 1-2.5mm (2.2-3.8 insul.)

with the battery live/earth its probably easier to pull one with a nice ring terminal on out of a mk2/3/4 and chop down to suit, then crimp the right MK1 fusebox end on

Thanks john, you really are a wealth of knowledge !
Should be buying a good temporary loom from someone so when I take the old one out I'll use it as a template.
I may even re route soom wires to tidy up the bay !
Dont suppose you know of a good supplier for the wires themselves ?
Would ideally like to match them all properly to save head scratching later on !

with the wires I have used various sources in the past, but if you want it 100% oem you'll struggle with aftermarket as there just isnt the selection of colours and wire gauges available. Since I've been doing looms for so long I have a healthy stock of wire stripped out of donor looms

what you might want to think about doing is get a mk2 gti pre-90 kjet or 16v loom. it will plug to your fusebox and almost all of it is too long so you chop off the cuddy engien bay ends and crimp on fresh terminals to fresh copper

just have to make sure the fusebox side is good is all, that'll save you buying a bunch of multimate pins. If you get a 16v loom theres a fair bit of extra wiring you'll want to cut out since you wont need the isv control unit, but the basic cold start stuff and sensor wiring is all the same.

with the MFA wiring you'll need to remove the outside air temp wiring and change the spade housing where your oil temp wire goes for the mk1 version.

All it is the mk1 outside temp is in lighting loom, mk2 its in the engien loom. you could keep the mk2 wiring as is even and convert the mk1 fusebox side plugs to connect ot it, if the mk1 outside temp wiring is knackered. the mk2 sensor is the same if its included

also the mk1 reverse switch wires are in the lighting loom, mk2 its in the engine loom so you can either choose to use the mk2 wires if better, or just cut them off. removing the multimate pins can be fiddly, the tool part number is 168-0528

Think I would prefer to use all new wires and connectors if I was going to make a fresh loom. Was thinking about running the loom through the wing and front cross member to hide as much as possible.

will cost you a lot, just depends how much you care about having all the exact wire colours and gauges. Also note a lot of the wires you find have the wire colours painted on top of the original wire, which is usually red. which can wear off. beggars cant be choosers mind if you need to make a new mega long run of a certain colour

if you stick with mk3 and newer wiring looms to strip your spares from they will all be excellent condition as all the plugs are fully waterproof unlike mk1/2 which uses a lot of unsealed spade connectors which let the water in to corrode the wiring.

plus mk3 and newer all use modern thinwall insulation wiring as well which takes a lot of the bulk out of the looms.

Thanks john ! Think I'll start looking out for donor looms then ! Got a original gti loom coming in the post to use as a template so will able to get cracking on soon !