ABY Wiring Harness Help/Identification

[S2central.net]

Further to some feedback - here's a revised version of the primer document - http://www.s2central.net/S2_Schemati...tic_Primer.pdf

I elaborated further on track numbers and how they are linked... Also reverse engineered how the various multicoloured connectors in the auxiliary panel map to the wiring diagrams... That then discovered a little correction I need to make on which cruise control schematics are correct for the S2/RS2. But I digress...

[S2central.net]

Found a couple of OBD funnies across the yrs on ABY / ADU schematics - its IMMO related - explains why there is three ABY loom versions for LHD and another three for RHD. Will catch this in a revised version this week. Its minor stuff, but its only when you have an intensive study on this stuff that you spot the anomolies - ask me in a week and I'll have forgotten.

[S2central.net]

New version available now - link is the same - http://www.s2central.net/S2_Schematics/ABY_Wiring.pdf

Includes detailed ECU pinout, some info about the various incarnations of looms across ABY and ADU - LHD and RHD. Also explains the OBD connector oddness, and I have elaborated with pinouts on the other connectors in the fusebox and auxiliary panels.

[Ruffiano]

I went through my loom last night labeling everything and getting it ready for the swap, this guide made it quick and easy. Paul, I'll forward you the ABY loom part number tonight.

[S2central.net]

I recommend you buzz it all out if you can... Boring PITA of a task, but much easier on a bench than when you have it in the car... Ball park its less than 100 wires so not too horrendous.

[david]

aby

nice work mate,this is going to be very handy when i start on my project...........

[Ruffiano]

I couldn't find the part number on my harness, It no longer has the sticker. Sorry.


Secondly I have a quick question, where does the power cable from the battery connect with the Fuse panel? Is it just in one location? I was thinking it is probably the same place as the L30?

[S2central.net]

Yeah there are some mighty beefy connectors that attach to L30 terminals on fat red cables - they can only come from the battery.

[bluequattro]

that s an awesome guide! You should do them for a living and sell them !
I ve now found the rpm signal wire for my stack unit.
Just don t know if it still exists in the wiring loom in the car-i didn t fit it remember.
Must be connected somewhere, when i give it revs the original dash display goes backwards ( negative revs, weird)
I m a teacher by the way, not a sparky, so this is all new to me!

[Ruffiano]

I did some work on the wiring of my car ('90 CQ, 7A) last night, Removed the old engine harness and put my new ABY harness in. It went pretty smoothly, stuffing all the wires through a small inaccessible hole (not sure if it is more accessible on the RHD) was not enjoyable but it needed to be done. All of the fuse box connections were a direct plug in. There were a few other connections that were on the hold harness that I don't immediately see. For starters the trip computer uses a small yellow plug that runs in the main engine loom, I don't see where this is in the ABY version, Also and more importantly the HVAC T5H connection doesn't appear to exist, I'm wondering what it looked like on the 3B harness since I believe that my cars wiring will be more similar to that. Also under my dash I had to unplug a few small round 4 wire connectors from the old harness to get it out, however they don't have a new plug on the new harness.

[S2central.net]

The yellow plug on the cluster is linked to ECU for MPG info via one of the other plugs - don't have data in front of me. Maybe you are referring to another plug - this could be a 7A specific thing. Photo would be good.

Also the HVAC integration is thru some generic location on the auxiliary panel. Will need to look that up - again might be a funny on a US based 7A.

Been running ragged here at work today so will try to apply some brain power to this later today.

Meantime - please post photos of any plugs you refer to with at least some wire colours to help me trace things on schematics.

[S2central.net]

T5h on the ABY loom - the red 5-pin plug... Look at the wires from Auxiliary relay positions 3 and 4 - they should find what T5h plugs into. Depends what flavour of aircon you have though...

[S2central.net]

Looking at Bentley for USA 90/Coupe and cross checking to page 46 on my wiring guide...

T5h/1 (green/black on ECU side) would connect to Terminal 1/87a on AUX position 4 - this seems to be via a red 3-pin plug in the engine bay (T3d pin 1) provision in USA - black/grey wire.

T5h/2 (black/yellow) will have to connect to a new relay block in AUX position 14 for your afterrun pump controller

T5h/4 (blue/white) is the R pin from MFTS - this comes via T1h on the USA engine loom - a white 1-pin connector on right of engine bay. Connect T5h/4 to Pin 4/HLS of the AUX position 4 relay.

Thats as much as I can gleam from Bentley - see section 87-10 if you have that for manual a/c or 87-20 for funky old digital system - which might be different again

[S2central.net]

Your OBD interface is indeed a 1-pin yellow plug in the Bentley for a 7A engine (T1c) - that needs to connect to ABY ECU pin 31 - maps to pin 3 on T5 at the auxiliary panel - see page 47 of my guide.

[Ruffiano]

Wow, you have an amazing understanding of these systems... When I get home this evening I'll take some pictures, I also want to send you a picture of my ECU, it is chipped but I have no idea what chip it is... Need to get some homefries!