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Discussion Starter · #1 ·
Rightio kids I know im really on the wrong forum for this but here goes, its a 1.8T wiring question, but to do with wiring the engine loom into a mk2

right, I whipped my engine and loom out, disconnected everything from the old engine, back to the ecu and traced it all back, leaving behind looms for wipers, indicators, fogs, headlights, horn and outside temp sensors and eventuallly got back tot he little grommet behind the servo.

13 wires was all that went through into the fusebox. All went back tot he three white connectorson the back of the fuse box, I labelled those 1,2 and 3 to help me, 1 is closest to the door with the fusebox in place, for the reason that when you remove a mk2 fusebox it turns around on itself so it was the right order when I stuck the labels on

so, I cut the following wires to remove the loom

Connector 1

pin 1 - Oil temp sender - Green/black

pin 3 - Coolant temp sensor - Yellow/red

pin 10 - High oil pressure switch - Yellow

Pin 11 - Low oil pressure switch - Bluc/black

Connector 2

Pin 3 - Fuel pump relay - Red/Yellow

Pin 5 - Ground on Cylinderhead - Brown/White

Pin 8 - Oxygen sensor power - Red/White

Pin 10 - ECU power - Yellow/Black

Connector 3

Pin 4 - Engine Block Earth - thick brown

Pin 5 - Digifant ECU pin 1 - Thermotime switch (what even is this lol) - Red/Greed

Then pins 6 and 7 which are reverse light switch related

So, I obviously have the engine loom from the donor car, the part connected tot he coilpacks etc is all still plugged intot he car. I just have one connector that goes to the ECU (smaller of the two) and one 8 pin connector which connects to the other part of the loom. Then the various plugs like maf and lambda etc (not everything has a plug, but im not worrying about that for now)

Then I have a big mess of wires going to 2 x 28 pin connectors that used to live in the back of the clocks on the donor car. I do have a wiring diagram for the donor, which is hard to follow as this is literally my first venture into electrics beyond fitting a head unit.

So do I just trace the wires from the 1.8T ECU that did the same jobs on the donor and connect them up?
 

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The only dubious connections there are the brown/white to the cylinder head as this would be a switched earth instead of a constant earth.

The only real problem will be with the immobiliser,you'd obviously need the ECU reprogrammed so it doesn't need to talk to the clocks from the donor car (in fact any modern clocks) before it'll let the engine start.

Chris.
 

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Discussion Starter · #3 ·
Explain to me the difference between switched and constant earth lol

I think I am going to have to get Raymondo to remove the imobiliser from the ECU altogether.
 

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Any solid coloured wire doesn't change its state,so a solid brown wire will always be grounded.But if it's got a coloured tracer (white in this case) then it won't always be grounded,it will switch from neutral or +ve to ground.

Chris.
 

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Discussion Starter · #5 ·
lost me, so its not just a case of joining that wire to whichever one is marked as the cylinder head ground coming from the ECU (everything goes from the engine to the ECU then into the car on my engine, but then you knew that lol)
 

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The head won't normally have it's own dedicated ground (although some do have for the coil packs),it's normally grounded through the head bolts into the block and then onto the chassis.

Chris.
 

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Discussion Starter · #7 ·
So I may have a missing ground teather somewhere. Something to think about as I go I suppose.

So the rest of them you reckon I just identify the wiring and join it all up?
 

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Maybe,grounds are more important than a lot of people think and assume wrongly that there'll find a ground somewhere else.

But for the rest just tie them in one big knot and be done with it[:DD].

Chris.
 

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Discussion Starter · #9 ·
it nearly got rolled down the street on fire at several points during the week lol, watch out for some pics and a story in members rides later on.

Its quite funny, or would be if it was happening to someone else lol
 

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Discussion Starter · #12 ·
Ive never felt like setting my car on fire and leaving it before.
I have a bad temper, ever tried to fit front beam bushes to a mk2 without a press or vice?

Its a sure fire way to test if you are capable of killing someone.
 
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