WR-engine - Wiring harnesses

[Knut Arne Glesne]

(X-posted to urq at audifans.com & quattro at audifans.com)

I'm currently in the middle of the engine-swap of my '86 Coupé quattro.
The new enige is a WR from the UrQ, and the ECU is MAC-01C.

As I found the wiring-scheme for the MAC-01C, I started wondering what
all the other wires and connectors were...

One of the harnesses is to the ECU. I've found all the right colors and
connectors.
URL: http://home.no.net/glesne/Temp/ECU-harness.jpg

But there's still two harnesses left.
I've taken some pics of them, too:
http://home.no.net/glesne/Temp/Harness1.jpg
http://home.no.net/glesne/Temp/Harness2.jpg
I guess these are the harnesses for the other sensors and stuff, sensors
that not have anything to do with the ECU, such as
low-oil-pressure-gauge and stuff.

The reason of my questions, is that I wonder if I actually have to
install this harness as well, or could I just use the one currently in
my car? I haven't ripped it out yet, it's in some hoses that includes
wiring to the lights and stuff. So I didn't want to rip it all out until
I had to...
My car has (had, actually...) the KV-engine.

And btw: What's this thing actually?:
URL: http://home.no.net/glesne/Temp/Thing.jpg.
I know it's a part of the ECU-harness, but actually what is it? I'ts
supposed to be installed behind the dashboard somewhere, should I just
put it on top of the ECU?

BTW2/OT: Check out these pics as well:
http://home.no.net/glesne/Temp/CupraR_1.jpg
http://home.no.net/glesne/Temp/CupraR_2.jpg
I've had this car to play with for 24h now, just had to give it back to
the dealer.. It's a Seat Leon Cupra R, fwd with Audi S3-engine (210hp),
Recaro-interior, 18" alloys and Brembo-brakes... Fun stuff!
But here in Norway it costs 59000 USD or 60500 Euros...:-(

Knut Arne Glesne
´86 Coupé quattro (Soon with turbo!)
www.glesne.com