I thought you might have seen it but thought I’d put it on just in case.
I was looking a few months back at this so searched my history and dug it out just in case it was any use to you wasn’t sure if it would be ! Worth a try.
Ok a few more photos per request.
Let’s start off with the back of the airbag. It basically takes the main plug, the big yellow one, center right, and splits it into the harness which controls the buttons on the wheel and then controls the horn and airbag on the other end.
Closer shot, everything is three wire with the airbag having four grounds.
The plug, bottom right, with the yellow “string” looping around it, is perhaps the most difficult plug to disconnect that I’ve come across. It took me an hour just to figure out how to separate it from the rest of the airbag module so you can change the airbag cover.
The three wire plug which plugs into the steering wheel harness.
The main yellow plug on the airbag plugs into this receptacle which is part of the clock spring assembly and pokes through the back of the steering wheel when you install it.
Moving back to the center console, here’s the plug on the back of the drive select switch.
It too is a three wire arrangement.
The plug itself is an 8 pole but only uses three positions (wires).
So how did you remove the plug with the yellow string around it ?
Also can you explain how to change the airbag cover as I have just got a carbon steering wheel for mine and am thinking of getting the air bag cover either in carbon or Alcantara !
Thanks in advance dude 
That was THE hardest part of the whole endeavor. You basically have to figure out how to pop it out without breaking it. Not easy but I have some detailed shots so you know what your’e dealing with. I will hopefully have a video done by Monday on just the airbag cover alone.
Just understand the whole process can blow up in your face, literally, as it’s an explosive device. I don’t know how hard it is to set one off that doesn’t have electricity running to it and I don’t want to find out! But just be warned, you could injure yourself, severely, messing with an airbag. I play with gunpowder all the time (reloading) so I know the risks, LOL.
Sounds fun lol
That would be great if you can have pics and a video nice one
I read in your first post that it was a pain to do that’s why I asked as I can then hopefully not lose anymore limbs
Thanks buddy
Steve, yes, that would be my preference too! 
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Have you definitely got a good ground on that stud? Difficult to see from the picture but it looks like it’s mounted in plastic?
Check the continuity between the stud and the chassis or negative terminal on the battery to ensure it’s good.
That part of the harness works fine from a power standpoint, I plug everything in and you can see the bluetooth module flash/blink signaling it has power. It’s just the steering wheel side. No power or so it seems as either button does not light up and none of the steering wheel controls work. Almost all of the aftermarket add-on buttons I see mate to cars with a four wire .
Sounds like it’s not receiving power from the airbag, you know or can easily find which pin the power comes in on, and should be able to trace that along the harness to make sure each button is receiving power. I use a thin piece of safety wire attached to the positive probe of my meter, you can push the wire into the back side of the electrical connectors where the wires are inserted until it makes contact with the metal termination. Chase the 12V to each button module when the harness is fully connected and make sure it’s going in on what would be the positive wire of the module (looking for mis-pinned cross connections). Make sure the other meter lead is on a good ground.
Chasing the ground would have to be a continuity (ohms) reading BUT you absolutely must disconnect the airbag if you do this, the meter injects a voltage to get the ohms reading and injecting voltages to airbags = party time!
The fact none of the steering wheel controls are working would suggest a cross connection or mis-pinned connector. Also, I’ve seen terminations crimped onto the insulation of the wire instead of the metal conductors, this would show if you do the voltage checks above through the back of the connector.
That’s helpful James and was going to be my next step. I actually did strip some thin wire to wrap around the probe to find the center console signal wires.
And I’m with you, the pinout on the new harness is not in the right place to power everything or there’s a bad connection. Luckily I solder up guitar wiring harnesses in my spare time and even came up with my own solder-less connectors for quick pickup swaps. 
But beyond pots, caps, resistors and simple circuits, I get a bit lost.
Beast (Amar) over on Audizine also sent me a few diagrams that’ll hopefully help me get all this working correctly as he sells this stuff. I’ll be sure to post the solution once I get it all done.
Also do a quick tug test on the wires going into the terminations/connectors to ensure they are securely located or locked in position and not being pushed back when connected to the receiving connector, seen that many times which is confusing as you will see the correct voltage at the termination but it isn’t making through to the other side.
The wiring diagrams from Amar will really help make this an easier process, give me a shout if I can assist in any way, I’ll hold the flashlight while you make the smoke happen.
Michel, how did you go ? Get the buttons working ?
Not yet, it’s a pretty invasive process involving pulling part of the MMI and control buttons and soldering in some new wires. I’ll also likely have to rewire the steering wheel itself to bring it back to a 3-wire setup. So for now, the buttons just sit there and look good, LOL.
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Hey Ape. Ever get this figured out? The wheel I just received had the same exact issue. 
Nope. I really hate wiring and trying to figure out stuff like that so I’ve just left it. Wasn’t helped by an entire spring/summer of 100 degree plus days either. I did almost nothing to my car as a result. If I have time this fall, I may give it another go.
Ugh. Just received the same kit with my wheel 3 days we’ve been trying to figure out what we did wrong. Luckily I came across your thread. messaged the seller already. They sent me the same instructions you have as well. The 2 pictures. lol
I have instructions. Just fitted it to mine and it all works Installation Guide For R8 Wireless Button (Update).pdf (2.6 MB)
Not sure which buttons you purchased. I told the seller it was for rs5 b8.5
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I’m waiting for a response on finding the drive select wire. Once I get that I will post.
I’ll have to go in and take another look. Buttons are just there looking pretty at this point. Thanks for the info.
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