ABY Wiring Harness Help/Identification

[Ruffiano]

I have a spare fusebox here I can photo and assist if required.

Again anything you are willing to photograph and post will be quite welcomed.

[S2central.net]

OK - I'll start on this tonite.... be advised that SOME wire colours change with model years and S2/RS2 variant so it won't be 100% perfect for all applications...

[S2central.net]

So lets start with the big grommet at the bulkhead where we can see the main strands of the ABY loom... We have five branches at this point -

1 - To the ECU - wrapped in yellow tape

2 - The heavy insulated section into the engine bay (details to follow)

3 - A skinny bundle that connects to brown 2-pin plug T2s (more on that later)

4 - Another skinny bundle, yellow wrapped, to the coding plug (T6d) and pressure sensor (F96)

5 - Big yellow bundle to the fusebox with a mass of spaghetti at the end (details to follow)

[S2central.net]

My piece of **** Nokia phone is dying so photos are coming slow here...

[S2central.net]

Bundle 1 is self explanatory with big 55pin connector to the ECU.

Bundle 2 requires some explanation - lets look at the branches as they appear starting from the bulkhead grommet.

2.1 - F75 (hydraulic oil level switch), T8e and T8f - Note T8f is denoted '1' with a sticker and T8e denoted '2'

2.2 We have quite a lot here -
T4g brown - input side to POS for cyls 1-2-3
T4n black - input side to POS for cyls 4 & 5
T3k white - fused power to coils 1-2-3
T3aa white - fused power to coils 4 & 5
T3o blue - to G66 via firewall plug panel (FPP) - knock 1
T3n green - to G61 via FPP - knock 2
G69/F60 - Throttly body
T3l black - to G4 via FPP - Crank reference
T3m grey - to G28 via FPP - Crank speed

plus a thicker branch at the same location containing

N80 blue (EVAP)
G62 white (Coolant Temp Sensor at rear of head)
N71 grey (ISV)
Manifold earth eyelets
G42 black (IAT on inlet manifold)
5 x injectors in the order you'd expect with Cyl #1 nearest the last connector in this branch for G40 (CMP)

2.3 is the 3rd branch with Z19 & G39 for lambda

2.4 is F21 (spades) and F34 (2-pin grey) for hydraulic servo pressure and brake fluid levels into Autocheck

2.5 is a special branch for G70 (MAF)

2.6 is a grey 2-pin T2aw - which is handoff point for a 2-wire loom extension to the WGFV... This circular connector slots into a clip on the left chassis leg below the MAF hose.

2.7 is T1 (a white spade) for the starter solenoid feed - black/red wire here

2.8 is the last item on the branch as a hooded black wired eyelet - with no denomination on the schematics - it is for the oil temperature sensor - down near the oil pump... This connects to the centre console guage.

[S2central.net]

T2s in that 3rd main branch stays inside the cabin - it goes to the centre console where it connects to the oil temp and pressure guages.
As shown here - http://www.s2central.net/S2_Schematics/C/C50-08.pdf

[S2central.net]

My loom is from an MY95 car - so tracks to this schematic - a multipage PDF - http://www.s2central.net/S2_Schematics/C/C50.PDF - thats where all the connector labels come from.

[S2central.net]

I've covered the 4th branch already... Only the fusebox mayhem now...

The yellow relay block is for J155 - afterrun in auxiliary position 14

The big black multipin also goes to auxiliary block and is denoted as T5 and T10 on the schematics - it is BOTH of these in one package

A beefy earth strap connects to the A-pillar near the aux fusebox

T1f - blue/red wire - behind the dash where it connects reverse lights from switch F4 (via T8e).

T6r - black multipin - picks up low coolant switch F66 and radfan connectivty to afterrun

T5h - red multipin to afterrun and ECU via T8f

87a - a black spade with two green/black wires that attaches to fusebox terminal

S24 - blue
S25 - red
S27 - brown
S28 - white
S32 - purple

L30 - large white spade with red wire - connects to fusebox terminal

O - grey wire on a white spade that connects to fusebox terminal

B - black multipin connector for the fusebox - includes the 'BS' fuel pump activation

M30ac - green spade with red/black wires that connects to fusebox terminal - this is south side of S21

T2x - black (OBD power)
T2y - blie (OBD blink)
OBD L-wire as red/white eyelet

[S2central.net]

Oh then there is what I call the 'ancillary loom that extends from the two 8pin multiplugs (T8e and T8f). Its as follows -

G22 (aka G68) for speedo sender on gearbox - 3pins with only 2 used
F4 2-pin reverse switch

F76 - MFTS as 4-pin block
F98 - spades for thermoswitch on water rail
V51 - afterrun pump - oddly 3 wires into 2-pin connector

G10 - blue spade
F22 - black spade
F1 - white hood

Thats all for now - there are MANY photos transferring to my machine - I'll try best to sort them into a useful format tomorrow.

[S2central.net]

My phone corrupted all of last nights connector pics - bahstid - so patience please while I do it all again... Will be worth the wait I promise with LOTS of info to help folk get their heads around this one.

[S2central.net]

Solved the single brown/yellow wire mystery - that isn't strictly part of ABY loom - its from a car with manual aircon... Tracks to pin 87k on the fusepanel at Relay #6.

http://www.s2central.net/S2_Schematics/B/B76.PDF - Track 16 - via red 8-pin connector in middle of dash

[Tonks4x4]

Solved the single brown/yellow wire mystery - that isn't strictly part of ABY loom - its from a car with manual aircon... Tracks to pin 87k on the fusepanel at Relay #6.

http://www.s2central.net/S2_Schematics/B/B76.PDF - Track 16 - via red 8-pin connector in middle of dash

I am still going to stick to my theory.... of its the supply to ATD.

Track 1

G17 to G106 with the black plug being T1o

[S2central.net]

Brian - that is equally plausible... perhaps more so actually... I am in the middle of creating the mother of all ABY wiring guides here !

[Ruffiano]

Brian - that is equally plausible... perhaps more so actually... I am in the middle of creating the mother of all ABY wiring guides here !

I'm excited to see that guide.

I have a bently manual for my coupe, it has the wiring diagrams. I have always thought I had a decent knowledge of electronics, however I don't really understand the layout. Is there a guide to understanding the diagrams?

[S2central.net]

I'm including the 'dummy's guide to Audi wiring' - you will like !