WIRING in a Mk3 Golf 1.8 20v TURBO Conversion!

Hello guys, I'm Super Ron, welcome back to the channel and we are back on the Mark 3 Golf 20 valve turbo conversion. You saw it in the previous episodes, we got the engine all sitting in.

And as it turned out, the Mark 3 is a perfect platform for getting these engines in. It all went in on the standard Mark 3 mounts.

In this episode, we are going to move on to the favorite part of any conversion for me, and that is the wiring. I've covered the 20 valve turbo conversion in the Mark 1s and the Mark 2s.

But in this Mark 3, it is even easier than ever. Because this car was electronically fuel injected from the factory, that saves us a lot of jobs compared to what we had to do on the Mark 1.

It's already got the fuel tank, the fuel lines, the internal swirl pot in the tank, so that side is all taken care of already. And because it was electronic fuel injection, we have an ECU.

So the car and the fuse box is already set up to run an ECU, injectors, sensors, lambda sensors. So all we have to do is make the Mark 3 loom to the TT loom.

Whereas in the Mark 1s, we had to put our own fuse box in and start from scratch. The Mark 3 fuse box is already ECU compatible.

So on the standard Mark 3 GTI, the ECU sits up here, and there's the ECU plug.

That then comes around the loom and it connected to the engine via this multi-plug.

It's also got the separate plugs for the knock sensor and the crank sensor.

I guess they didn't want them going through the plug to save interference.

You kept the shielded cable with that. Also got the starter.

And the alternator wires there. Back here, we've got the electronic speedo.

And the reverse, and up here, we've got the coil wire.

Because it was a single coil with distributor, not a multi-coil pack system like this.

But all we need is the main ignition live from that.

Over this side, I don't know if you'll see it, down here is the factory lambda sensor.

So we got all our powers and feeds for the lambda heater.

The only thing is, I was hoping to take all this loom out.

But it is part of the main headlight and fan loom. We're going to keep the fan controller.

And all the sensors and the plugs to run the Mark 3 system.

So coolant system wise, that will stay all Mark 3.

And that's got this little module, I don't know what the variables are.

But that'll just sort out fan speed and everything for that.

But this does mean we have everything we need right here to run an ECU.

And all the connections here that will go back to the clocks.

So we've got our water temperature, our oil pressures, oil temperatures, injectors feed, sensors feed.

All going into the engine there.

This is where that multi-plug went in.

There's the knock sensor and there's the crank sensor.

That was there, so all the oil pressure, all pressure on the end, coolant temperature.

All go out of this plug and then to the clocks.

So we can tap into it all there.

Here's the factory ECU from up in the bulkhead.

So this side is all Mark 3.

This side is all the loom out of the TT.

So this goes to the ECU plug.

So as I'll put it in the same place, that's going to run up there, around, then the ECU is going to sit up there in the factory place.

And then in the similar position to the Mark 3, the TT also has its plug here.

So when we took it out the TT, I chopped off the car loom as well.

So it's going to be as simple as finding all the wires we need in here and connecting them in there.

Then this will sit nicely all down there, running into the Mark 3 loom.

So it'll make a nice, neat conversion.

This one on the wiring diagrams is called the T14i plug.

And that is where it connects to the TT loom and then into the TT body harness.

There's a few in here we won't use, like oil level sensor and bits like that.

But everything else we've got.

And then up at the ECU, we've got all our ignition lives, our positives.

Everything else, we can tap in there.

So this is the main engine side of the loom.

And then this is the car side of the ECU loom, so this is where it connects to the rest of the car.

Where it gets all its powers, its feeds, everything else.

So I've just unwrapped all this, because some of it we're not going to need.

So let's have a look at this spaghetti.

And here it is, all laid out. It looks a bit of a mess.

But when you know what everything does, it's not as daunting as it seems.

So we've got our main plug that goes to the ECU.

We've got our relay box.

We've got our lambda sensors.

Got some other sensors.

And then we've got the connections where it used to go into the TT car loom.

So I've chopped these out the TT, but we probably won't be using these, because we'll be chopping these wires down.

But if we do, that'll just make a nice neat connection where we can go plug to plug.

There's a few extra ones on here, because we are going in a Mark 3.

That we haven't used before, and because this is a BAM as well, there's a few extra ones.

So if we start over here, we've got our main ECU.

We loop around to here, these are our lambda sensors.

That's the rear lambda, that's the front wide band.

So we won't be using the rear, but we will be having the wide band.

Because we're on the Mark 3, we're going to keep the purge valve set up.

So that's going to stay.

We're also going to keep the power steering sensor, so it knows the load on the power steering system when you're turning on lock.

And then because we're a BAM, we've got the exhaust gas temperature as well.

Over to the fuse box.

We've got the air flow meter plug.

And then we've got our main relay for the coils.

And then that's the feed out to feed the coils in the main engine loom.

And then if we go to all our inputs, we've got all our colored plugs.

The blue one is the throttle pedal, so that'll stay the same.

The orange one has got a few bits that we will use.

It's got the TT reverse lights, we won't be using them, because we're keeping the Mark 3.

But there's a few in here that should give outputs to the Mark 3 miles per gallon and things like that to make sure that all works.

We've got the black plug, which is the brake switch.

And the clutch switch.

We've got the brown one, which is our main powers in, and it's also got the starter trigger.

But we'll be using the Mark 3, so we don't need the starter.

But this is our main ignition live in, our main power, our trigger for the fuel pump relay and our feed for the lambda and air flow meter.

And then on our white plug, I don't think there's a lot we've used from this one.

There's the can bus wires, which we're not using.

And a few others, then obviously our blue one.

Is for our pedal.

So we start with our main battery power, which is the red and green in the brown plug.

That needs to go straight to the battery via a fuse.

That will go down, that gives its main power to the ECU.

It also tees off that and goes to this relay, which is for the coil.

The ECU turns the relay on when it wants to start, and that sends power down to the coils.

So it will be able to shrink all this down, because remember we're putting the ECU where the old ECU is.

So we're going to have all our powers around this area.

Not all the way over there.

So the way it works, the ignition live is only really a wake up for the ECU.

And then the ECU decides what it wants to turn on.

On some conversions, people just run an ignition live to everything.

The problem with that, if you have a fuel line split, the engine will stop, but your fuel pump will be on ignition live.

So that just carries on pumping and pumping and pumping.

Whereas if it's controlled by the ECU, as soon as the ECU sees the RPM signal has stopped, that will shut off everything to the car.

So of course, that's how we're going to wire it in.

The Mark 3, because the Mark 3 wiring and fuse box is already there.

We can tell our BAM ECU to turn on the Mark 3 fuel pump.

Which also sends power out to the injectors, the lambda and the sensors.

So all we need to do is merge them together.

So there's not really a lot that we're going to cut out of this one, we're just going to shorten everything down a bit.

What you've seen me do before is put the fuses in here.

This is usually the extra relay slot for the secondary air injection.

And they have the fuse in there as well.

All these fuse holders are empty.

But because we need to get our power from the battery.

When I've been looking at the wiring diagrams, we have a few variables in wire size.

So I've been on with my little bit of therapy and going through the wiring diagrams.

This is the wiring diagram for the Mark 3 engine.

And there is page one of five, so there's only five for the Mark 3.

But on the TT, we have 13 pages.

So it just shows how many more sensors and how much more wiring there is in the TT engine.

But I've just been going through, working out what I need and where I need to put it.

That round plug that goes into the side of the engine is called the T28A.

And then the slash is which terminal is on that plug.

So if we look at oil temperature, that goes up into the fuse box and then off to the clocks.

Through the T28 pin number eight.

So we'll be able to find that with the wiring colors and know what we need to connect to.

And the plug in the same place on the TT is called the T14i.

So with this, I know which terminals we need to connect together.

So the six wires that we always connect to the little fuse box in a Mark 1 conversion.

Are the ignition live, the battery live, and then we have four fuses that are connected to the fuel pump relay.

We have our air flow meter and lambda feed, our injector feed, our sensor feed and our fuel pump.

All of which are already powered by the fuel pump relay in the Mark 3.

So all we need to do is get our BAM ECU to activate the Mark 3 fuel pump.

And all those will come live.

So the only thing I did notice when I was going through them is wire size.

For instance, the ignition live going to the BAM ECU is a 1.5 mm wire.

The ignition live going to the Mark 3 ECU is only a 0.5.

The injector feed is fine, that's a 1.5 mm.

Going out of the Mark 3.

And the injector feed in the BAM is a 1.5 mm.

The lambda feed in the BAM is a 2.5.

But we do have the coil wire in the Mark 3 that is a 1.5 mm.

The only thing with that, the coil on the Mark 3 actually isn't fused, that goes straight to the ignition switch.

So what I'm probably thinking is I'll put a fresh live and a fresh ignition and locate them in that little fuse box with the relay.

Just to make sure we have maximum power going in.

And then everything else will take care of itself.

So probably a lot of talking, but I do get really excited about wiring.

So as always, let's protect this lovely black paint.

Nice.

And let's get unwrapping.

And there we are, all spaghetti'd up.

So we can see all our pin numbers now.

So we can go to the wiring diagrams and work out which wires are which.

But even so, we have got all the pin numbers for the terminals in there.

Which will line up with the diagram.

So fuel pump trigger, plug T68, ECU plug.

Pin 31 should be yellow and blue.

24, 25, 26, 27, 28, 29, 30, 31.

So this is what activates the fuel pump relay in the car.

So now the BAM ECU is going to switch this.

And that will liven up everything for us.

Fuel pump trigger.

Purge valve.

T6833, green, yellow.

Purge valve.

Let's have a look at this T28A, snip out what we need.

T28A, pin 4, injector feed, red.

Coolant temp.

Pin 23, red, yellow.

Oil temp.

T287, green, black.

Now the TT doesn't actually have an oil temp sensor on it.

But it has got the oil level sensor that we won't be using.

So I can use that wiring to run to the temperature sender.

Through the loom and then up to our dash.

Oil pressure, yellow wire.

T28, pin 13.

Oil pressure, blue, black.

Pin 12.

And another one going into the Mark 3 engine bay is the fan run on thermal switch.

Which is T2811, a brown, black.

Mark 3 thermal fan switch.

And what that is on the Mark 3 engine, it has this temperature sender.

Which doesn't actually go to anything, it's just bolted into the inlet manifold.

And I think that's a bit of a like an ambient air temperature.

That gives an input to the fan module.

I don't know if it'll be happy if it's disconnected and not worry.

But I'll probably will try and get this in.

So the Mark 3 coolant system will all work as designed.

And I think what that's for is if the coolant temperature is all okay, but you shut off the engine and the engine bay is really hot.

That'll just carry on blowing the fan through the bay for a while.

So I'll try and keep that reinstated.

And then the remainder on the plug are the throttle body, the ECU coolant temperature, the dizzy hall effect and the injectors.

So they won't be needed, so we can chop them off.

And these are the ones we want.

So they will be disappearing, but I will just leave them in, because this could be a handy track to get wires from here up to here.

But for the plug, see you.

And there is the ECU plug, all accounted for.

Everything here, we don't need.

The only ones we really need from here is we've got the fuel pump trigger wire.

We've got the purge valve and we've got an ignition live.

I did end up finding a big ignition live in the wiring diagram that runs off a relay.

So that's all fine.

All the ones in here, we've got the throttle body, the injectors.

There's a couple of wires for an auto box, if it's an auto.

Air mass flow.

Engine cooling.

Intake air temp.

Lambda.

Knock sensor.

Coil trigger.

Dizzy hall effect.

So all of these we're not going to need.

The one we could have done with up here, this is the lambda sensor.

But it's only got the three signal wires.

The feed for the heater, which is what we need.

Comes out of the fuse box, which is just under here.

Comes through the bulkhead and then straight to the plug here.

So this is our Mark 3 lambda plug there.

Three of the wires go up the loom and over to where we're starting.

But the main power wire, which we need, comes straight out of there.

And the wires are a real pain on this, because they come from the bulkhead right behind the brake servo.

So just like the Mark 2 C2, you can't get to the wires coming through the bulkhead without taking the brake servo out.

So what I think I'm going to do is connect down into the plug there, and that's where we'll get our feed up for our lambda heater.

And on the BAM, that also powers the air flow meter as well.

Also on this side, there's this little purple and white wire.

Which was pin 10 on the ECU, and that's just labeled as going to the radio.

Which is a bit strange why the ECU would see the radio.

So I'm just going to keep hold of those two, they're in pins next to each other, 10 and 11.

So that might be what we need for the trip computer.

So I can snip the rest of this spaghetti off.

And start on the BAM spaghetti.

So the first ones we can get rid of, brown plug, pin 3 is for the starter motor on the TT.

But we're using Mark 3.

So, see you.

And on the orange plug, pins 3 and 10 are the reverse switch on the TT.

See you.

We have got some wiring that needs to go inside the car.

The blue one is for the throttle pedal, so obviously that needs to go in.

The black one is for the brake switch.

And then the clutch switch wire is on the white plug, pin 4.

So what I'll do.

Is I'll put that with these to go in the car.

And then on the orange plug, pin number 1, the gray white is for our K line of the OBD port.

So we'll snip that off.

And that's going in the car as well.

So that's pin number 1 on the orange plug.

Pin number 2, I believe, is the consumption signal.

So we'll connect that to our purple and white in the Mark 3 loom.

And hopefully that'll get a miles per gallon reading.

Pin 3 and 10 were the reverse switch.

Pin number 9, we're going to need this, this is our RPM signal to the clock.

This is green and brown on here.

But on the other side of the orange plug, on that pin, it is actually green.

Which is all the same as the Mark 1, 2 and 3 Golfs.

So they never changed the taco signal wire.

6, I believe, is a speed signal, not going to need that.

And I've just found them on the wiring diagram, pins 7 and 8 on the orange plug go to the aircon unit.

So that tells the ECU what the demand is.

So we'll just get these two out of this one.

And then what we have left on the white plug.

We have pins 2 and 3 are the can bus to the clocks.

So all the signals for everything just runs through can bus, but the loom is also wired up.

So if the car isn't can bus compatible, you've got all the signals going through as well to the clocks.

The only one we're going to need from this one, I'm going to put in is the DFM to the alternator.

And what that does is lets the ECU monitor the alternator, so if there's a big battery draw, like you've got your radiator fans on.

You've got your blower fans on, you've got your heated rear screen, you've got your radio on, it can adjust the revs accordingly.

So we will connect this one up.

And we've got our part of the loom that's going to go in that area for the power steering switch.

So this can run with that.

And then that'll connect up into the alternator.

Orange plug is done.

On the white plug, don't need our can bus.

We've got our alternator signal.

And the rest are just for the controls to the dash.

Which we don't need.

We've got our clutch switch.

So white plug is done.

So we don't need these, so I can depin them out the ECU.

And all that can go.

So our last plug is our brown, which is our main power in.

So we've got our ignition live, we've got our main battery 12 volts.

We've got our lambda sensor main power.

And then we've got the trigger for the fuel pump relay.

So our ignition live and our trigger will sit up by the ECU.

And we're taking them from the old ECU.

Our lambda feed is the one we're going to have to take down to the old lambda sensor.

And to the old ECU, there wasn't a permanent power.

So I think I might run this one to the battery itself.

And for that, we can shorten it.

Right back, because that power goes inside here.

I'll put a nice little fuse in.

And then because this will be in the engine bay close, that can run straight to the battery.

I think that'll be the neatest way.

And that'll keep all the factory splices, so we don't have to go in anymore.

So we'll have one fuse in here, which will be the main ECU battery fuse.

Then it can just come out of there and go to the battery.

Right, so now we know where everything needs to go.

Let's lay it in the bay and then we can start chopping all this down to size.

Oh, and the other thing, all the ECU earths are spliced together.

And then they have just a little ring connector that sits up in the scuttle.

And quite handily on the Mark 3, we have a proper earth stud here.

Even though it wasn't used on the Mark 3.

That's just a mount for the old ECU bracket in there.

Then the top hole, I just reused the hole that was already there for the alarm.

So now our little box.

Slot on there.

Lid fits on.

That looks like a nice factory install.

Well.

Once all the spaghetti's gone, anyway.

The other thing I've done is instead of running them up and around here and trying to get the plugs through this grommet.

There is a hole here where the old clutch cable used to go through.

So I'll get the clutch grommet back on.

That just means we can run our wiring through there.

And then it goes through this trunking.

So that'll be a much neater route.

I've just popped inside and whipped the clocks out.

Because I want to make sure this RPM signal does go all the way to the clocks.

But I've unplugged it.

I don't know what VW are playing at, but every wire is white.

Very strange.

So I've got to find out what pin is the RPM signal.

And then we'll buzz that out to the wire that was by the ECU.

But yeah, I was hoping to find all our normal colors here.

But obviously not.

In a Mark 3.

So a quick Google shows that pin 10 is for the taco on the clocks.

So I'll link that in, and that didn't go to the coil.

But then I found green, black, which goes across, and I'd labeled it as automatic.

Because where the star is, that says only on automatic gearboxes.

But our green, black wire.

Connected to pin 10.

Does give us a beep.

So that is our taco wire.

So I'll put that to the ECU.

I also pinned out our miles per gallon wire to the clocks.

And that is pin 26 on the clocks.

So that routes through.

So that can go to the ECU as well.

So now we've confirmed our connections, I can shorten these down and connect.

So I've ended up running everything along this trunking.

It all comes through the hole that used to be for the clutch cable.

Comes down through there.

Pops up into this trunking.

Then that runs this way, even the lambda runs along.

And that'll drop down out the end here.

So that'll look really neat when that's all clipped up.

So we've just got our last few connections to connect into that mess.

Now, most of this isn't going to be used.

And most of it just goes from here down there to here.

So we could just chop it off both ends.

But that is not the Super Ron way.

So I'm just going to unwrap from here to here.

And then we can just get rid of all of this.

Doesn't need to be here.

And see you.

And what I've decided to do with the purge valve.

Instead of running the 20 valve one all the way around, having to cut the plug off, swap all that around.

The Mark 3 wiring is all there.

And up to our looms here, so these are the wires for the purge valve.

So I'll just join them into the 20 valve and then that ECU will work the Mark 3 purge valve when it needs to.

And all connected up.

So there was only five connections we needed up here in the end, there was ignition live, rev counter, miles per gallon consumption.

Fuel pump trigger and purge valve.

So they can be wrapped up.

And that will sit down in the scuttle there.

And the other thing I wanted to check, just that's sitting on the TT mount.

But that does sit quite high.

So, just wanted to make sure that the scuttle fits in.

And it does.

Loads of room.

Just let these plugs on the front.

This is the Mark 3 loom.

The starter cable to the battery.

Fits straight in.

Starter motor.

Clips straight on.

That's for the alternator.

This is the TT start and charge loom.

And that comes down, down and down, and that used to go up to the old battery post.

And that's going to be a bit long.

I think what I might do.

Is fit the start and charge loom from the old Mark 3.

And that'll go straight onto the starter.

And we've got our little blue wire for the battery light.

So I'll whip this off and stick that on the alternator on the car.

You can see the Mark 3 and the TT.

The Mark 3 one.

Sitting there.

Perfect.

So before we connect new to the old, I just want to finish off our twos.

And that does include the oil pressure sensor.

So on the Mark 4s, TTs, everything of that era, very traditionally, it just has one oil pressure sensor.

And it's a really simple pressure switch.

It has a little contact in there, when oil pressure goes in, that opens up the contact.

When the oil pressure is down, that closes the contact and puts the light on.

But for some reason, on the Mark 1, 2 and 3s, it's a bit more complicated.

They have a low oil pressure switch and a high oil pressure switch.

So the dash needs to see that the oil pressure passes this one.

And then passes that one, otherwise the buzzer goes off.

So we need to fit both of these onto the TT engine.

And luckily, just like in all our other conversions.

You can just simply replace the standard TT one there.

And then there's a little blank there you can take out and put in the second one.

So then you just wire them in to the Mark 1, 2 or 3 wiring.

And the dash stays happy.

But on this, we've got a third sensor.

Because on the MFA, because this is a GTI, it also has.

Oil temperature.

So we need to fit a third sensor in.

So we'll take all these out.

These do need to be wired the right way around, because the dash gets very unhappy if it doesn't.

And there's different colors on these for different oil pressures.

And if you peel this one back, you can see this is the blue wire.

Goes to the blue sensor.

And the yellow wire goes to the white sensor.

So that's nice and easy.

It's not always that way around, there's lots of different variants of oil pressure depending what dash you've got.

But for this one, it is.

So we'll get them out.

Get this out.

And then I have a plan on how we're going to get it all to work.

And then on the Mark 3, we've also got our fan thermal switch here.

So this is just a temperature sensor, and I think it's for fan overrun when the engine bay is still a bit hot.

That just continues the fan.

So I'll just see if I can find somewhere to put that on the block as well.

So here are our two oil pressure sensors out for the dash.

And they can go in those two holes.

And it will be happy.

But we're going to try and get this oil temp in as well.

So for that, I've got this little T-piece joiner.

So that will screw in one of the ports.

We'll put one of the pressures there.

And then we'll put the temperature in there.

These are all M10 by 1.

So they all screw in together.

And that one can go on the port there.

Then we'll try and fix this in the bay somewhere.

Ideally, you'd like the oil temp to be right in the galley.

So it touches flowing oil.

But we can't put the two oil pressures in there.

And there, because the threads aren't deep enough for this to go in.

Luckily, the oil temp is a lot shorter.

So we'll get all this together.

Get that blanking grub screw off.

And we'll be good to go.

And the TT one screws out.

And you can see visually, they're the same length, same thread, but they have a different plug.

But they are different pressures.

So you can't use these for a Mark 1, 2 or 3 clocks.

You have to use the original ones that come with the clocks.

And they all go in like this.

Got our three sensors in.

Got our oil pressure, oil pressure.

Annoyingly, as I did this one up until it was tight, that did put the temperature sensor right around the back.

So I just had to bend the tab a bit so it didn't hit the casing there.

But we can still put a spade on there.

Spade on there, spade on there.

So we've got the oil pressure wire.

That used to go to the TT one.

So we can put a spade on that there.

But we need two extra wires for here.

So out of all our wires that are going to the engine.

So the ones that we are going to be joining from this plug.

Are our injector live.

We've got our sensor live for the actuators.

We've got our oil pressure light, the one that we have got.

We've got our earth.

Violet, coolant temperature to the dash.

We've got our live to the speedo sensor.

And the signal to the speedo sensor.

And then that comes down the main earth.

And then we're left with these ones.

And two of those go down to the oil level sensor in the bottom.

And we're not actually using this.

There's no oil level distinction on the Mark 3 clocks.

So I can use these wires and reroute them to here.

To our two extra sensors.

And then we can wire that in here.

What different people do, sometimes they use the vehicle speed sensor wires.

Ones that aren't used, and then they drop them to the oil pressure.

But we're using our vehicle speed one, but we can use the oil level from the bottom.

So we've got our oil pressure yellow.

That'll go to our factory wire.

Because that's on the end here.

We've got our oil pressure blue, black.

That'll go to the blue sensor.

And our green and black is oil temp.

Which will go to our temperature.

Our injector feed will feed the injectors and the sensors.

And then I've just got to extend the speedo wires.

To join into here as well.

So let's reroute this wire from underneath.

Up to here.

So I've just fed that up through, that drops down behind where the speedo sensor is.

And comes out there.

We've got three wires, but one is an earth.

So we've got yellow and black, purple and white.

And strangely on this side, we've got yellow and black and blue and black.

But on this side of the plug, it is purple and white.

So we've got pins 11 and 12 on the plug go to here.

So we can chop this plug off.

Put them to our two sensors.

And join this to our loom.

Keeping it all looking nice and fresh and factory.

Of course, we could just extend these wires and have them running along the front in here.

But this will make a much nicer, neater job.

And if you ever want to take the engine out, it'll all be removable.

And all connected up.

And I've used the boots and the clips from the Mark 3 loom, so that will protect it.

And also, it will stop them getting mixed up.

So now we've got all our twos.

Let's do our froms.

And we're all together as one.

So these were mainly the sensors for the gauges, we've got oil pressure, coolant temperature, oil temperature, speedo.

And then we've got the big powers for the injectors, the sensors and a big earth.

The other one I didn't mention was the brown and white in pin 8.

And VW have done their little up wire, down wire jump again.

Because this 2.5 mm wire here, all it does is the earth for the coolant temperature sensor.

So this one's 0.5, this one is 2.5.

But at the actual sensor itself, we've got brown and white there.

And that's only 0.5.

The same as the signal.

So I'm not sure why they do that.

But I've joined both the earths together.

And they're going to go to an earth point.

Probably up to the battery.

And then we're only left with one wire, which was pin 8, purple and black.

But this is on the TT side, remember.

On the engine side, in pin 8.

It is blanked off.

So that must just be the standard car loom.

And that does something else on a different engine.

So we can get rid of that.

We've still got that fan override sensor.

Not sure where I'm going to do that, I can't really find a place to do that.

People do say you can just get rid of it.

So we'll put that as a maybe.

I've extended the reverse wires, because they did come out over there.

So now the reverse comes up to here.

The Mark 3 starter and alternator fits.

And that runs through to the alternator.

We've got all our oil pressures in.

Oil temperature.

This one's for the boost pipe.

So that'll go up there.

Everything is pretty much coming together now.

All the main power and earths are just from the Mark 3 for the starter.

So we've just got a couple of powers left.

And as always, been writing everything down in my little Bible, so I know what everything does.

So all we've got is the power for the lambda.

To connect up to the old lambda sensor.

And then we need to power the main relay with a fuse.

And then we might be at key time.

And there's the Mark 3 lambda plug chopped.

I only need the power source from it.

Which is the white and red, pin 1, and now that feeds the red and blue into the TT loom.

But remember, that's actually powering the blue and yellow in the TT loom.

So the rest of the Mark 3 lambda sensor is terminated up the top by the ECU.

So we can neat them up, wrap all this up.

One more to go.

So for the battery source, I've just popped this out of our little relay box we put in there.

And we ran the red and green wire down, which is the main battery feed for the ECU and for the relay.

But as we're out here and we're not going to go back in the car.

I'm going to run this straight to the battery here.

So I've got the proper terminals to go into there.

And then that makes its own fuse box.

I've got these for another Caddy build, you might have seen.

They slot in.

Then the fuse goes in there.

And then I've got another one on a fly lead.

So these will be our two sides of the fuse.

And the red one will just go straight to the battery.

And that'll sit in there, little beyond.

Relay there, fuse there, all nice and tidy.

So let's clip these in.

Work out our length and then I'll just put a ring terminal to go to our battery.

So these just click in like a normal terminal.

One, two.

So you can see now we have terminals sitting in there nicely.

So that sits in there nice and tidy.

So I'll run this back out the grommet.

And then measure it up this way.

And wrapped in some conduit.

Got a red marker on the end, so we know.

We've got our fuse in.

So I'll connect this up to here.

So it can stay there.

And in perfect timing.

We've just got our ECU from the TT back from VAGtronics.

We send it to them to de-mobilize it.

Because on the TT, they're immobilized in the clocks.

So there's no way around that.

We also get them to delete a few things like the secondary air injection.

Where this didn't have it.

Rear lambda, which we have had deleted.

On a Mark 1, we often get the purge valve deleted.

But we're keeping it on this one.

So that's all in and ready to go.

Also on this, I wasn't sure whether we're going to need a taco adapter.

On the older stuff where the coil triggers the rev counter inside the car, they need this special box of tricks.

Because the ECU puts out a nice, crisp, square signal.

Whereas the coils just put out a bang, bang, bang, bang, bang signal.

So the clocks aren't ready for it.

On the Mark 3, it does run from the ECU to the clocks already.

So I'm not sure whether we're going to need this yet.

But I've got it just in case.

The other thing we need to do, because we're using the Mark 4 coolant temperature sender.

That will read incorrectly on the dash.

So we've got a little resistor to go in there.

So I'll be wiring these two up inside, just behind the dash.

Comes with all these instructions, all nice and easy.

Just needs an ignition live, earth, output from the ECU.

Input to the clocks.

So I'll try and fire it out first.

If the rev counter works, then sweet.

If not, we'll wire this in as well.

Right, so I think we are all wired up.

And all plugged in.

All the TT loom is still plugged in there.

All the Mark 3 bits, the starter, the charging is all plugged in.

All the signals to the dash are all done.

I think we're about ready to put some electric to it.

And see what happens.

So I'm just going to put the battery on first.

Turn the ignition on, check we've got alternator light.

Check we've got oil pressure light.

And then I'm going to turn it off again, put the ECU on.

Because I haven't got fuel lines on yet, and if I turn it on, the fuel pump will most probably prime.

And we don't want that squirting all over the place.

And if that all goes well.

We'll see what happens.

Little false start, battery's flat.

So I've got the jump pack on.

See if we have dash lights working.

Yeah, we have battery.

Oil pressure.

Got fuel in the tank.

Let's give it a go.

That's a good sign.

Right, let's put the ECU on.

And find out which one of these fuel lines is the feed.

I'm pretty sure it is the top one.

So let's see if the fuel tank primes.

Yeah, so that is the top one.

Fuel lines on, official.

I've just wired up the OBD port.

So I just want to plug it in to make sure it's all happy.

Before we go for a start.

So obviously this will be inside the car eventually.

I've just plugged the throttle pedal in as well.

So that's all happy.

I think as the ignition's on.

We should.

That's a good sign.

Means the ECU is alive.

And it is reading it as a 2001 Audi TT BAM.

Engine codes.

A lot of these are going to be old codes.

When we took it apart.

Clear codes.

No codes present.

I've just got all the front all tidied up.

I've got all the factory 1.8 turbo brackets back on.

So all the mounts for all the plugs and the wires are all there.

And everything's clipped right back into its factory holes.

So that just means it's all nice and secure and safe.

We've got our power steering sensor back in and all clipped in.

So the ECU can monitor the load on the power steering.

Also got all our alternator all plugged in.

And the wire connected up for the DFM, so the ECU can monitor the load on the alternator.

And adjust itself accordingly.

Because this isn't part of the start charge loom.

I'll put it on a plug, so it can be detachable.

So we can take the start charge loom all out.

That's all in there nicely.

We're using the standard Mark 3 start charge loom.

The standard Mark 3 starter wire, alternator and the reverse on the top.

All the big cables are standard Mark 3, and they just run up to the battery terminals.

Same with the earth, that bolts on in the factory place.

All runs up in its clip to the factory place.

So it's all come together as a nice, neat and tidy conversion.

We've got our ECU at the top.

And this is the Audi TT bracket, and I've just drilled some holes in the bottom.

So that bolts in nicely.

So that's all nice and secure in there.

And that fits in there really nice.

Got all the loom all taped up.

And I'm really happy how we've managed to run it all through this factory cowling here.

So we've got the lambda coming out this side.

That runs down.

You can just see it down there.

And that runs to the lambda sensor on the exhaust.

Everything else runs out this side and down.

So I just kept it to a nice, neat, tidy install.

We've still got our bits to go inside the car.

So we've got our throttle pedal, brake switch, clutch switch.

And OBD reader.

And they're all going to run through that little hole there.

We've got all our power management sorted.

We've got the main relay, we've got fuse.

And that runs up to the battery in our little conduit pipe.

The only thing we haven't wired in yet is that little fan override switch.

Most people just ditch this.

And I can't find anywhere to screw it into at the moment.

So we might not connect it.

But I've just left the wire there just in case we do in the future.

So I think everything's all back in.

Put the alarm back up.

That's mounted properly.

Everything just looks really nice and neat and tidy.

And tidy.

So I'm pretty happy with that.

So we've got the pedal to go inside.

But I'm a bit restricted at the minute.

I can't get in very well.

So we're going to do that in another episode when we're off the ramp.

This is the Audi TT pedal that I took out with the engine.

But a lot of people did mention there are other bolt-in alternatives.

Apparently the Mark 3 TDI did have a drive-by-wire pedal.

And also the 1.8 turbos in the CRB, which is on the same floor pan, also had drive-by-wire.

We have got this little pedal box.

And I think this is the Seat conversion.

That just has a little motor.

We have put this in one before.

So that's one alternative.

But this pedal box has been modified.

So we have got that as an option and repin it.

And that just works on the standard cable pedal.

But that moves a little actuator.

I think this is out of a Mark 2.

So that is one option.

But I have found a company, just like what we've put in the Caddy, that do a bolt-in panel.

That that bolts to that, and then that bolts into the floor.

So I think we're just going to do that, that'll be the easiest way.

And we don't have to remove the pedal box then.

So I've just bolted a bit of the down pipe on.

I've cut the bottom off, because that doesn't clear the mount.

But it's got the lambda in, and that'll just be enough to give us an exhaust.

And obviously, it hasn't got the boost pipes on, so it's going to be a bit unhappy about that.

But, it should still run.

Fingers crossed, first start.

Fuel pump primed.

Oh.

Not happy.

But it's alive.

And relax.

So that all went really well.

Fired straight up, first time.

Obviously, we've still got a lot of work to do with the plumbing.

But electric is good.

Let's just see if the rev counter's working.

Right, let's have a look if the dash is working.

So we should have battery light come on.

Yeah, battery and oil pressure.

And let's just see if oil temp is working.

Miles, miles per gallon.

Oil temp.

Rev counter works.

All the gauges are okay.

Even the fuel gauge.

So that's a bit strange.

So maybe we've got a problem with the alternator.

So I have just found another one in the shed.

So I'll swap that over and see if that solves it.

So wiring wise in the bay.

I think we are all done.

So this episode has probably gone on quite long.

And it's been quite a lot of talking.

I do get carried away with the wiring.

But the wiring is the question most people do ask about on these conversions.

So hopefully, this has been nice and helpful for you.

We have had it up and running, but I haven't run it for too long.

Because obviously, we haven't got water in the system at the moment.

With no radiator.

So in the next episode, I'm going to fully plumb it in.

We've just had the intercooler arrive, so I can put all the boost pipes on.

We've got all the bits to put the water pipes on.

We can get this fully plumbed in, get all the little bits and pieces for the brake vacuum.

For the purge valve system.

So we get everything plumbed in and run it right up.

So, I hope you've enjoyed this episode as much as I have doing it.

As you've seen, wiring is definitely my favorite part of any project.

And is the bit that scares most people, but if you understand the wiring diagrams.

Understand what does what.

Isn't that bad.

So make sure you give this video a like.

And be sure to tune in to the next episode.

The Mark 3 videos have made the graphs go absolutely through the roof.

You really seem to be enjoying this build.

So hopefully, that will carry on.

And we'll get many more episodes getting this up and on the road.

We've got all the bits in now to do all the plumbing work on the car.

So I'll see you next week for that.

But until then.

Make sure you have fun.