Connecting A4 glove box changer with concert head unit problem


Registered User
Jan 7, 2010
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Hucknall, Nottinghamshire
Hi all,

Can anyone help?

I have 2005 A4 Avant B7, and thought it would be a good idea to fit a 6 disc glove box changer, so I contacted audi and told them I had a concert head unit (model 8E0035186D) and was told it was suitable for a changer (model 8E0 035 111D) So I bought one off of ebay, and a cable (MFD2)

The lead fit on the back of the changer, but to my horror when I removed the head unit I found no spare port to plug the 8 pin plug into.

Has anyone got any ideas where I go form here?

I imagine that's because there's a changer cable already installed. You just need to unplug it and use your new cable. Even if there is no changer cable there will still be a plug connected if you have the Bose system as one of te pins is used to earth the Bose pin on the same plug (which flattens the EQ for that lovely woolly Bose sound), so if you have Bose then this will be occupied. It's connector B shown below:
Hi Andy, thanks for your response, nothing ever seems easy these days, I think I have been sold the wrong lead, my terminal looks different to your picture though. I have tried to put a picture on here, but I will not work, my pin outs are as shown in this link ( Concert )

The cable I was sold will not fit any of my terminals, so I am really stuck now. Do you know which lead I need to get?

The blue connector is the mini ISO changer plug. You will have either a multicolored 21 pin mini ISO in the HU at the moment (blue/green/yellow) or if you are unlucky a single black connector. This connector plugs into the top connection on the back of the HU:

With the multicolored connector simply slide off the blue part and slide on the new one. If you have the solid black one you're a bit stumped as you can only plug in the blue changer plug with the whole of the black connector unplugged. Unplugging the black connector means you lose the feed to the rear amp (or front & rear amp on Bose). You can either buy a PIE pass through adapter:
Or you need to extract the pins on the blue plug and insert them into the corresponding locations on the black connector. You'll need a pin removal tool to do this.
Thanks Andy, I can almost see through the fog now! Typically I have the black 20 pin connector which explains my confusion. So just to clarify, I buy this pass through adaptor and plug it into the HU along with the blue connector, then plug the 20 pin connector in the the adaptor and then finally It should work. If this works then you are a genius!!
Ok, sorry but I'm back again. My harness addaptor arrived the other day, so I rushed out to the car to connect it all up, only to find that I can't get the changer to work. It seems that I can't get any power to it, nothing lights up, so can't load any discs., the only thing I do get is some random beeping coming through the speakers sometimes, but can't figure out why that is happening. When I press the menu button on th HU I'm not even getting the option for operating the changer. I am totally baffled now, I don't know if I have dodgy leads or a dodgy changer. Any ideas what I could try next?
What happens when you press "CD"?
You can unplug the changer from the adapter and plug it directly into the HU (with the 20 pin connector removed) just to eliminate the adapter
Sorry I was being a bit thick, obviously the changer cable is already plugged directly into the HU, DOH!
Usually this is because the ground is missing. These adaptor harnesses only carry everything for that third of the cable, the ground pin is part of the middlegreen bit of the block on an Audi as shown on Andy's post.

SO you need to ground the CD changer, is there a brown cable sitting doing nothing? Usually that is the case with the CD changer cables.
Yep, your definitely missing the ground wire. That is why nothing is powered up.

Look on your radio the pins are shown, ping 10 of the 20 pin connector is CD GND. And that is not connected to anything.
Ahh thanks!! so let me make sure I understand what you are saying, as I am a bit of a simpleton when it comes to electrics. I have looked at my 20pin connector and there is no wire in the CD GND port, but my harness adaptor does have a black wire coming out of it and going to the middle green plug ( pin 10). So I could route a new wire to an earthing point somewhere then either run it through hole 10 in the 20 pin connector or tap into the black wire that somes out of the harness adaptor and earth it that way. is that correct?
Basically you need to ground that CD changer somehow, a simple test would be to run a piece of cable from chassis metal of the car to the metal of the CD changer case. If it bursts into life then that's the issue.
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