I had an MDI lead that worked fine.

I also had a BT loom that worked fine.

In order to save space behind the Columbus I decided to combine the two by chopping the MDI extension (Loom to controller) and adding it to the BT loom.

I was careful to label the pin location of each wire as I took it off the MDI loom so I knew where it should go on the BT loom. I also double checked it against this list on My GTI, but did have one wire unidentified - wire is grey has 'Blau B10' printed on it and is identified as Pin 3 at the MDI end (in the My GTI list, this pin is unused).

End result, I have working BT, but odd behaviour from the MDI (it doesn't work but recognises that it is plugged in).

Let me explain: With all the wiring in place (but no MDI controller plugged in, the Columbus shows 'Aux' in the top right greyed out as always was before MDI.

With the controller box plugged in to the MDI extension wiring the top right soft button shows 'MDI' greyed out.

So it know the box is plugged in... And it shows as '2E - Media Player 3' in 19 - CAN gateway (and is ticked).

On the Columbus menus (Setup > Media) I can tick or untick 'Activate AUX Input'. With it unticked the Columbus goes back to showing the 'Aux' greyed out.

In 37 - Navigation I can't see any options to change to do with MDI.

In 2E - Media Player 3, I can't change the only option there which is to do with Aux monitoring.

Also, the CD Changer still works where as it didn't before I combined wiring looms.

Apart from the obvious (I wired it to the wrong place but I'm convinced that I didn't) - what else could be wrong?

Should have added that when I plug my phone in using the iPhone to MDI cable it does not charge up, makes no sign that it is connected to anything and does not appear on the Columbus. This is probably why the Columbus 'MDI' is greyed out 0 it can't see that anything is attached.

I suspect that it is something to do with either the 'spare' wire from pin 3 or the CD Changer requiring additional wiring somewhere (probably the first one).

I have a USB cable and could try connecting a thumb drive of music if anyone can give a good reason why trying that might help identify the problem.

You must have some of the wiring in the wrong place

I have made several combination looms without any issues

Pin 3 is the mute and goes to pin 10 on the audio plug

Thanks Eddie, but according to my notes, that's where I've got it (I haven't checked in the car as it's dark and cold).

Working off this diagram taken from My GTI, (I think) this is what I have:

MDI ....................................Headunit.................... Wire coding/colour (probably specific to my wiring)

Pin 1 Ground .................... Block 2 pin12 ............ Braun 1 (grey wire)

Pin 2 CAN Low.................. Block 2 pin10 ............ SWGE (grey wired twisted)

Pin 4 NFR+/AUX R+......... Block 4 pin 7 ............. Brown wire

Pin 7 12V ......................... Block 2 pin 15 ............ Rot 7

Pin 8 CAN High ................ Block 2 pin 9 .............. SWWS (grey wire twisted)

Pin 9 NFL+/AUX L+ .......... Block 4 pin 1 .............. White 9 wire

Pin 10 NF-/AUX- ............... Block 4 pin 2 ............. Black sheath

Pin 3 Mute ........................ Block 4 pin 10 ........... Blau B10 3 (grey wire)

If someone can confirm that the first two columns are correct (it all matches my notes made when I removed the MDI extension from the pass through loom) then I will go and remove the combined loom and double check everything.

If all else fails, I'll get Eddie to make me a loom... but I'd rather not part with any more money at the moment.

looks like it is correct, however i would double check all your connections

di you solder them?

Thanks. All were soldered and heat shrink wrapped.

Looks like I'm going to have to remove the looms and check everything....

i know you stated that all worked before, try it again with the cd changer unplugged

I'll giv it a go.

Would removing the plug behind the CD changer be sufficient?

I believe that it must be hard wired into the original HU wiring.

yes

Failing that, presumably checking some voltage differentials at the Columbus end of the loom might highlight any dodgy connections without taking it apart first???

Some quick checks today - and perhaps I have wired it correctly!

It works with the USB cable I have and a USB thumb drive (most of the time - it seems that I sometimes need to unplug the USB cable from the MDI unit and plug t back in to recognise the USB drive, but this may have been caused by my trying to scan the controller measuring blocks at the same time.)

To my mind, this suggests that cabling / wiring / soldering is OK and the phone is at fault (I have had problems with it for the past few months in terms of using power connectors / docks / etc.)

Here's some info from VCDS if that enlightens anyone to anything...

Address 2E: Media Player 3 (J650) Labels: 5N0-035-342.lbl

Part No SW: 5N0 035 342 B HW: 5N0 035 342 B

Component: SG EXT.PLAYER H13 0090

Revision: A1001003 Serial number: 7667670119

Coding: 010000

Shop #: WSC 00000 000 00000

VCID: 26490F6C51D15D287B0

No fault code found.

Wednesday,16,January,2013,12:47:00:13904

VCDS Version: Release 11.11.5

Address 2E: Media Player 3

Control Module Part Number: 5N0 035 342 B

Component and/or Version: SG EXT.PLAYER H13 0090

Software Coding: 010000

Work Shop Code: WSC 00000

VCID: 26490F6C51D15D287B0

Advanced Identification

Serial number: 7667670119

Identification: SJA-001

Revision: A1001003

Date: 14.11.09

Manufacturer number: 0001

Test stand number: 0288

Flash Status

Programming Attempts(application): 0

Successful Attempts(application): 0

Programming Status: 00000000

Flash Date: 0000.00.00

Flash Tool Code: 00000 000 00000

Software

Diag: 03.00.00

CAN: 01.11.05

TP 2.0: 03.04.00

KWP2000: 03.00.00

OSEK-OS: 03.08.00

OSEK Net: 03.69.00

Misc.

Hardware number: 5N0 035 342 B

Workshop System Name: J650

VCDS Info:

Labels: 5N0-035-342.LBL

How much power is needed for a USB drive as opposed to an iPhone?

If the USB works then it has to be the phone or the ipod lead

Agreed.

With a bit if jiggling the cable in the phone, I can get the phone to charge but not to register on the Columbus!

Looks like I'll have to find someone else with an iPhone (not 5 or 4s I believe) and try theirs...

At least I seem to be able to rule out the wiring. Hopefully.

Managed to borrow an iPod touch today - plugged in and....

Worked first time

Logical deduction is that it is my iPhone that is the problem which fits as I have been having problems with the dock connector, but I thought that had been resolved. Seems not.

New dock connector on order (less than £5) and I'll fit that to the iPhone as soon as it arrives and, fingers crossed, it will then work with my phone.

If not, I'll be starting another thread about how to go about getting an early upgrade to my phone...

Thanks to everyone for their advice and comments.

Glad you got it sorted mate. Before you combined the looms, did you have two quadlock connectors into the back of the Columbus, and did it matter which way around they were ordered? I'm assuming it shouldn't but that space is very tight.

Adam

The reason I combined them was to avoid having two pass-through Quadlock looms behind the Columbus. There's barely enough room for one...

I knew that that the MDI loom didn't allow the CD changer in the boot to work, but the BT loom did. So I chopped the MDI extension off and soldered it into the BT loom.

And the CD changer does work. As does the BT and the MDI - so very happy with that.

The new dock connector for my iPhone arrived today so that will hopefully fix the phone being the problem (am awaiting a new power switch for the phone and will do both replacements at the same time.

No I know about the lack of space having fitted my BT loom recently.

Have you lost aux-in?

Never had Aux-in working (it was greyed out in the top right of the Columbus screen) as I have not Aux socket.

With the MDI plugged in it (not surprisingly) shows MDI in the TR. If I unplug the iPhone / USB drive the 'button' goes grey. If I unplug the MDI controller, the 'button' reverts to greyed out 'AUX'.

Ah ok thanks. Fingers crossed that the kit I have just purchased has this behaviour then as I'd like to keep that if nothing else as I have it now!

Thinking about it by combining the looms in the way you say, you have effectively put the mdi loom behind the bt loom behind the columbus and kept the cd changer so I will try that order first (if I can find the space!)

Cheers

Adam

Where BT wires & MDI wires need to go to the same pin, they are joined at the same place on the pass through wire...

I believe that CD changer is retained as there is one pair if wires on the pass through I am using that don't cross over (as they do on the MDI pass through.

I'll take a look.

Thanks mate

The reason I combined them was to avoid having two pass-through Quadlock looms behind the Columbus. There's barely enough room for one...

I took the HVAC controls out on mine....plenty of room.

(Although I did need the aerial extender/splitter for neatness)

I took the HVAC controls out on mine....plenty of room.

I hadn't thought about that! Thanks.

I need to remove the HVAC controls to add TPMS switch soon, so will re-route the pass through qualdlock connectors down rather than to the side.

Does anyone know why the cd changer is disabled by installing the standard MDI loom please?

It seems only one of the necessary wires is not passed through the loom for some reason, but I don't really understand why this has to be the case?

Thanks

Adam

EDIT: Looking in detail, I THINK the only CD wire not passed through the MDI loom is the switched positive at pin 10 block 4 - this is a blank at the "in" end of the loom. At the "out" end of the loom which feeds into the head unit, there is a pink wire running from pin 3 at the MDI unit into pin 10 block 4, which I think from reading earlier in this thread is a mute (so effectively also a switched positive).

Can anyone suggest a reason why I shouldn't try splicing a wire into this pink wire from the CD changer (which seems to be suggested by the thread below).

http://www.mytreg.com/index.php?/topic/7113-install-rns510-media-in-mdi-interface-into-centre-console/

I suppose my main worry is why the harness doesn't do this in the first place?

Any help understanding this gratefully received.

Update, spliced wires as suggested above and kept the cd option and the mdi works fine. I do wonder if both the mdi and cd player are actually on at the same time, but if so only the selected item is outputting sound, so fingers crossed all is fine.

Adam