EU Spec fully electric rear seats retrofit...

[Oli18]

http://cgi.ebay.de/Audi-A8-D2-Sitze-...item4838760de0






I would love to buy this

I wonder if he would have the wiring loom, door buttons, parcel shelf and if it's from a non Limo version...

Wish i had more time and money

Oli

[IT]

Ok, so we had some reasonable weather on Sunday, so time to get cracking on this project before I forget completely where all the bits went

So, Heres how my car looked at lunchtime....









And then by 3 pm:






And here is the carpet out of the car, sat next to the one that is going to go in. The original is closest to you, the new one furthest away. The front of the car is the to left of the picture, the rear to the right. Note that the rear of the carpet to go in extends by about 3 inches. This makes the car carpetted underneath the rear seats when the seat base lifts up and slides out. It wouldnt be the end of the world if you didnt have the carpet to install, but I do, so I shall.... After its given a dam good clean though !




Now the carpets are out, the next job is re-wiring. Wiring for this transplant runs the full width and bredth of the car. It connects to the ditribution panel above battery in the boot, into both rear doors for the new switches, into the passenger front door for the passenger seat memory, under the passenger seat for the memory and control for sliding the seat forward from the rear, and then theres the controls on the dashboard for lowering the rear headrests and the heater controls at the rear of the center console for the rear seats. I'm also fitting the wiring for the blinds whilst I'm at it.......

I previously dismantled the donor car loom and put it into neat, logical bundles but the weather has been so crappy lately its taken way longer to get going and I've forgotten what most of the wires did <doh> - Never mind, the wiring diagrams are excellent for these cars and after a few moments of pondering, I was back on track.

I've got a few logistical problems with regards to actually bolting the new seats in. The rear seat base is essentially the same for both cars, but then they are tailored by hand to spec, so there are some welds / threads / recesses that are missing / spare / excessive and I have to fix, but theres nothing too bad. The biggest pain I've got at the moment is I'll probably have to remove the LPG tank from the boot to get proper access to the rear buldhead, cest la vie .....

More updates towards the end of the week hopefully when I might get chance to get the soldering iron out and make some wires actually do something

[CliveH]

Looking good there Ian

[IT]

ok, we have a little more progress. I've also taken some slightly better photos (which I've resized you'll be pleased to hear) to try and explain some of the battle that lies ahead....

So, firstly here is a shot of a mockup of how the left hand side adjustable seat base sits on the car. Also there is a central plastic section that houses a large number of electrical connections. This sits inbetween the two moving seat bases when all installed.



Here is a shot of the other side of the car, without a seat base. I have highlighted the 4 holes where the base fixes. The front two are absent by default, and I've already used some rivnuts to fil these in (M8) and so they're not a problem. Bolt number 3 (top right) is a standard seat belt fixing from the regular seats, but number four (top left) is just a gaping inch wide hole as you can see. Its not the end of the world, I'm making a metal bar to insert into the hole with a suitable thread through the middle. This will give a nice tight fix within the box section....



These are the hooks that hold the standard seats on, but I wont need them when I convert so I have to remove them. This is d-day, once I cut these off, I *have* to make this work as there is no going back... !!



The hooks (green circle) are fixed to a plate which is essentially rivetted in, so I'm just going to drill out the rivets and they should fall out nicely....

The red circles are where the rollers for the moving rear seats are placed. There are two pairs of rollers per seat, this is a nice easy bolt through and tighten up - phew. The blue circles are some more absent lugs that I need but dont have. These will hold the upper center of the seat, which contains the armrest etc. This section is lower than the boot floor so I cant get behind it as I will hit the fuel tank, so its going to be a couple more rivnuts and screw in a thread that I can then screw on to....



Here is one of the 4 sets of rollers that will fit in the red circles



To sort this properly, and also to gain access to run the wiring looms and new RNS-E Tv Tuner etc I had to remove the LPG tank from the boot, hence the straps hanging in this boot shot. I've also hightlighted location of the rollers and hooks from the boot side. Note also the blatant cut out for the ski hatch, making retrofit a doddle if you so fancied.....



Wiring will be the next big priority, now I'm happy it can all be physically done without too much hassle....

[CliveH]

This is turning into quite a mammoth task Ian! Great stuff and top write-up as usual

[gninnam]

Looking good (rather you than me)

[IT]

So, Saturday 27th Feb, and a reasonable day for working outside, so a bit more progress made.

I've put the physical mounting of the seats on hold for the moment as I've satisfied myself its do-able, i now need to get the wiring sorted so that once it is done I can start on the mechanicals ....

First up, we have switchgear to install in both rear doors. Its 4 wires for this right hand rear door, and the connector passes through the door and existing grommit without too much grief:



Thw switch is used to to on or off the auto seat retract function so the seats move back into the most compact position when you open the door, it makes it easier to get in / out. It has 4 wires. 2 are a simple(ish) positive and negative feed for illiumination, so the buttons light up. 1 other wire takes a feed from the door-open contact in the relevant rear door, and the final wire is the output of this switch and it goes to a limit switch at the back of the reclining seat rail. The output of this switch then feeds into the rear seat setup itself... If that all sounds a bit heavy, try working it out first hand

The electric rear seats (and the heating which I'll do later) both need to feed wires into the boot of the car to get power from the distribution box above the battery. The problem is though that at the factory, they lay the wiring loom and then block the hole up compeltely with foam (arrowed):



Here is said foam remove, look how much there is !! - Dont even think of getting a wire through here without removing this stuff..... It comes out with some decent screwdriver prodding, but dont snag any wires...



Here is our nice clear gap through which we can poke cables now....



And to poke through, just pop the cables on a length of flexible conduit like this and poke through....



ok, so power sorted, we now need to feed the cables into the rear passenger side door:

There are 2 connectors in here. We have a 4 wire connector for the auto-retract function again, but also a 5 wire connector for the button that lets the rear seat passenger move the front passenger seat forward for more leg room. In summary, the forward/backwards switch in the front passenger seat is re-routed through this switch so that the rear switch is effectively connected directly to that motor, and it has over-riding control. There is also a +12 feed into the switch so that it has the power (physically) to drive to motor independently of any button being pressed on the seat itself. To complicate things further, this motor is quite a high power drain, so it has its own dedicated relay in the passenger foot well to supply the current, and this relay is activated again by the isolation switch on the drivers door - ie when the driver turns off the rear windows, it also turns off this button in the rear to the control the front seat. Neat, stops the kids playing with it etc....



I've had a few problems remembering exactly how the wiring loom sections I cut out went back together as the bad weather has delayed the implementation, so I've fortunately had the old loom to refer to :



I will say this now - Without the actual car to dismantle, I really cant see how anybody could attempt this retro-fit. You need so many bits and pieces, and reference points, that I find it hard to believe anyone else has every completed this retrofit - I honestly think changing the engine is considerably more straightforward than this and I definitely wouldn't have started it if I'd fully comprehended how tough it was going to be... !!

I've started now though, so I'll just have to finish.....

[IT]

Sunday 28th Feb....

Another reasonable day, so off we go again. Yesterday I got 95% of the wiring in place to support the electrical movement of the individual rear seats.....

Today, we move on to the next piece of the puzzle - The wiring for the movement of the front passenger seat, and the passenger seat memory....

So, I sorted out the relay and the feed from the drivers isolation switch, and tidied up a few loose ends from yesterday. The passenger seat memory has two main connectors, 1 multiplug connector to connect the memory module under the passenger seat (just like the onle under the drivers seat) and 1 multiplug connector to go into the door, also just like the one on the drivers side.

I had (stupidly) thought this was going to be quite straight forward, but nope. I lost about an hour and a half trying to find a red/green wire that connected to both the memory switch in the passenger door, and the memory module under the seat, and something else. The something else eluded me for ages, and even studying the loom for ages was still a puzzle.....

Eventually, I realised that the drivers seat and passenger seat aren't wired the same. There is one special 4 pin round connector for the 'move the passenger seat forward from the rear' switch, but I had 'assumed' everthing else was the same.

On a normal drivers seat, you have a square green multiplug which does heating mainly, and the square brown connector that does power, seatbelt height adjust, illumination etc, but on the passenger seat (and for reasons I'm still unsure of) the power from the brown connector is presented in a totally seperate black multiplug, and the brown connector remains with only the smaller current signals.... The green/red wire I was searching for is the only other wire in the black multiplug.

So, connected all of that lot up and looks like this now:
(green arrows show pre-existing connections, red arrows show new ones I have had to put in)



So, by the end of today I felt confident enough for a 'test'. Aside from forgetting a couple of earths, which were quickly rectified, the seat behaved exactly as thought - Memory works with the buttons in the drivers door, and the seat moves backwards/forwards using the button in the rear, but only when the drivers isolation switch is off.... Cool



And here is a shot in the rear, with the new switchgear circled....



Finally, a quick shot from the drivers side. Here I reveal my only 'cheat'. Every wire I've put in so far runs either to the orginal point of origin, or subject to current load I've piggy backed it on to a more local point of the same circuit. This wire highlighted here though was a PITA. It connects the drivers side memory buttons to the drivers side seat memory module to the passenger side memory module to the passenger side memory buttons. It connects to nothing else, and only exists on the drivers side on cars without passenger seat memory. I removed the full wire from the donor loom, but it runs the full width of the car behind the heater matrix, which is basically impossible to access without really, really stripping the car down, so I confess i've taken a shortcut over the top of the transmission tunnel to connect passenger side to drivers side. Its neat enough but I feel guilty I've deviated from the Audi build, so I've confessed all now



So, thats about it for today. I've just got two more looms to put in now. I have to run one for the reat seat heating, and a much smaller one which is just for the button on the dashboard to lower the rear headrests. That tiny bit of loom also includes the blinds switch which I need to pop in to make my reat blinds work.....

I've got a small concern over airbags at the moment, and I've still got to get the rear seats bolted in properly, but definitely feels like I'm over half way... <phew>

[builder22]

Hey Ian,

Thanks for the update - this is some amount of work. Should be worth it (hopefully) when it is all done.

Niall

[IT]

Originally Posted by builder22

Hey Ian,

Thanks for the update - this is some amount of work. Should be worth it (hopefully) when it is all done.

Niall

Heck yes...

Heres a rough Tally on man hours so far:

Collecting together all the parts needed from donor car - 3 hours
Stripping original wiring loom - 6 hours
Stripping out original car interior -5 hours
Cleaning new parts to go back in - 2 hours so far, loads to do still
Manufacturing bolts/plates to fit rear seats - 3 hours
Stripping boot / Gas tank - 1 hour
Installing rear seat wiring this Saturday - 7 hours
Installing front passenger wiring this Sunday - 7 hours

34 hours already, so thats a full week pretty much....

Glad I dont have to pay myself to do this, I couldnt afford it