[QUOTE=TriX5;727460Question, anyone know what the white mystery plug is for?[/QUOTE]

It'll be X322 or X400. Refer to the wiring diagram, it should be easy to locate.

Been trying to find a diagram online but no luck, where can I find one?

This afternoon decided to check the color coding on my new harness and all was well. I received the BM53 radio 2 days ago and I am now only short the CD changer which I am sure will be coming in soon.

In doing the color check I discovered 8 of the 10 speakers run through a single plug of the three on the amp. This plug contains no other connections. The remaining 2 speakers are connected to the main plug on the amp. I realized this would allow me to keep 8 speakes in the car connected while connecting the new harness to everything else.

So I connected the new OBM, the nav computer, and the new radio to the new harness. Then plugged in the new harness to the subwoofer and the amp (except for the speaker plug). Finally plugged the harness into the main plug to the car (first of the three connectors attached to the amp frame). This left two speaker connections in the new harness needing load which I hooked to a pair of old Pioneer speakers. Then hooked up the ground, turned on the power and voila!!

(one minor thing, there was a plug in one of the blank holes of the connector to the car main harness which I had to remove and insert in another blanks space, nothing crucial there).

As I don't yet have the GPS antenna couldn't navigate but otherwise the Nav computer worked fine. The tape deck faithfully played one of my trusty old cassettes. Radio was fine and B/T seemed operational. I am still in the dark what the red nav connector does but so far so good.

Conclusion: As far as I can see this is most definitively a plug and play affair and I am impressed that new loom is exactly correct for my '06. I would say that the only quirk indeed is having to reinstall the speaker wires all the way into the doors. Have to make a decision on that very soon now. I am stumped why dealers would refuse to do this retrofit, it is really easy, especially if you have all the clips and other hardware handy!!

So far I am thinking I will cut the existing speaker wires off the old harness and connect them to the speaker connectors on the new harness leaving the excess coiled under the carpet. However, I would have to find some connectors or at least pins that fit the speaker connectors, anyone have a suggestion where to get them?

Funny how I could plug everything in and run it quite without installing anything but it was worth the effort to know that all pieces were operational and that the car made no bones about running them. See below a couple of pictures of the affair, not very usefull as there is too much of a spagetti junction but there it is.

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Here's some retrofit instructions. For E38 but the loom is nearly identical

http://members.shaw.ca/dragnet/image...v_retrofit.pdf

I suggest if you have existing DSP then leave speaker wiring as is on DSP plug and just transfer the wires you need

All info is also in the WDS:
WDS BMW Wiring Diagram System - Model Selection

Project is a bit slow because of a medical hick-up on the domestic front. Finally making progress again this weekend. Still haven't figured out what the red Nav connector does but it sure does something. I connected things up today and the Nav does not navigate, I am stuck in Atlanta.... However, the Nav works fine on my 03 so something is not right yet.

Anyway, the new harness is in from the radio to the front with the OBM connectors sticking out just ahead of the shifter. Plugged everything in and music all works fine, the TCU works, can connect with BBerry and make calls, etc. So, the wires to the red nav plug is probably what is missing but as long as I don't know what that wire does I am a bit stuck there, BMW parts guys have no idea unfortunately.

I decided for the moment not to demolish the doors and therefore took the speaker wires out of the old harness. This means that temporarily I have a loom with just the old speaker wires running along with the new harness. Couple of pictures below to show the level of the madness....

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Here is a picture of the stripped old loom and of the new harness with the speakers wires added in separate bundle. The speaker connector in the new harness will be replaced by this one for the moment.

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The red connector contains the speed pulses, and reverse signal, and 12V ACC power.
The speed signals are crucial, if you have a Mk3 then the nav will not navigate smoothly without the speed signals.

Speed signals come from the ABS module, but you can also pick them up from other locations depending on what equipment is fitted.

PDC ECU gets a wheel speed signal.

Thanks guys, I found a little time to experiment with this today and the Nav works fine, I just didn't give enough daylight and time to find the sats. Now it is operable.

The time has come to start looking a sawing out the dash opening, not funny but has to be done. Anybody got a good hint on how to keep the debris out of the heating?


I have more pictures for a write up later.