[Quasimodem]

So the Ultimate Amplifier Wiring Guide appears to be correct as to the colors of the wires going from my amp to my speakers. But not the colors of wires coming from my HU to the amp.

After accounting for the output wires for the Amp, now there are Four twisted pairs which I can't track down:

The descriptions are color of the wire/color of stripe:

1 twisted pair -- White/Blue and White/Yellow
1 twisted pair -- White/Black and White/Green (Edit: this turned out to be the front left channel)
1 twisted pair -- Light Gray/Purple and Light Gray/Yellow (Edit: this turned out to be the front right channel)
1 twisted pair -- Light Gray/Green and Light Gray/White

These all appear to be HU out, four channels. Any Idea which is front, Rear, left or right?

[VP Electricity]

There was an earlier post indicating that the wires had changed colors, but that the pin locations have not changed colors.

If you refer to the earlier pin positions, you should be OK.

However, what I would do is put it a test track (or tune the radio between stations to white noise and leave it there), and put a voltmeter on each pair of wires, and move the fader and balance in turn to full L, full R, full F, full Rear, and verify that the voltage follows the fader and balance controls. You should also verify that the voltage changes with volume, because there is an early report that it doesn't, and while I don't believe it, you better make sure.

If you point out that this is a PITA, welcome to my world. I ran the biggest and best tech support department for years in the 90's, and I told everyone to assume I was lying to them until they tested my information. Always test.

If you don't have a voltmeter, you really shouldn't be wiring in a BMW. They are cheap.

Good luck and let us know how it goes!

[Quasimodem]

Okay. I was just in the process of matching the pinouts, but could you direct me to a pinout description?

In the thread I linked above, somebody did a pinout using numbers, well, I don't know pin 5 from pin 55, I will look to see if there are any numbers on the connectors.

Anyway, I took the two connectors (gray and black) out of the main cover and this is a diagram of the gray connector, looking at it from the front. I noted all the wires. It appears to be the Gray wires (the four in the middle) which have changed. I am going to remove those wires from the connector, plug everything back in, and see if I get any sound out of the front speakers.

Thanks.

Edit: Well, when I pulled all the Gray lines from the gray connector I got nada for sound (keep in mind my left front speaker is not connected). So I put the Gray/White and the Gray/Green back in (leaving the Gray/Yellow and Gray/Purple disconnected) and I had no front right channel but all the other speakers were working. I pulled the same wires on the black connector (White/Green and White/Black) and I still had the rear channel and the subs (my left front is disconnected so I presume these wires are for the left front). I will post the full pinout list later, but right now, it appears that the HU-to-Amp wires for the front right channel are Gray/Yellow and Gray/Purple, while the HU-to-Amp wires for the front left channel are White/Green and White/Black. Not sure yet which are + and which are - .

Yes, I did tape off all loose connectors in the process.

[VP Electricity]

No meter, eh?

Better tape them off so they can't short as you play it.

[Technic]

Originally Posted by Quasimodem

Okay. I was just in the process of matching the pinouts, but could you direct me to a pinout description?

In the thread I linked above, somebody did a pinout using numbers, well, I don't know pin 5 from pin 55, I will look to see if there are any numbers on the connectors.

Anyway, I took the two connectors (gray and black) out of the main cover and this is a diagram of the gray connector, looking at it from the front. I noted all the wires. It appears to be the Gray wires (the four in the middle) which have changed. I am going to remove those wires from the connector, plug everything back in, and see if I get any sound out of the front speakers.

Thanks.

Pin numbers are shown in connector X10266 here (pin 1 starts at the upper left corner going all the way to 13 in the very first row, and so on):



Pin assignments are here; just disregard colors, go by pin number and function.




Pins that are not shown:

Pin 5: 12V+
Pin 26: Ground
Pin 10: OEM remote

Notice that Power, Ground and woofer wires are 12AWG thick, and those are the flat blade connectors. The round pins are inputs and outputs with a 20-22AWG thick wires.

[Quasimodem]

Well that picture of the connector is great, now I see the numbers.

The Gray/Yellow wire goes to 9 (Front Right +), the Gray/Purple wire goes to 17(Front Right -).
The White/Green wire goes to 30 (Front Left -), the White/Black goes to 38(Front Left +).

This verifies my observations and now I know which ones are + and -. And I didn't even have to learn how to use a voltmeter.

One more question, when I adapt the balanced inputs to the RCA connectors for my Matrix, does the + go to the shield or the inner wire?

Thanks.

[Technic]

Originally Posted by Quasimodem

Well that picture of the connector is great, now I see the numbers.

The Gray/Yellow wire goes to 9 (Front Right +), the Gray/Purple wire goes to 17(Front Right -).
The White/Green wire goes to 30 (Front Left -), the White/Black goes to 38(Front Left +).

This verifies my observations and now I know which ones are + and -. And I didn't even have to learn how to use a voltmeter.

One more question, when I adapt the balanced inputs to the RCA connectors for my Matrix, does the + go to the shield or the inner wire?

Thanks.

Inner/center contact...

[Quasimodem]

Originally Posted by Technic

Inner/center contact...

Thanks. I guess I should have figured that out, since in a normal RCA cable the shield is usually the ground (negative in our cars).

It is a bit confusing because when using balanced inputs, one really isn't plus or minus, they both carry signals. If there was a negative wire, it would be a third wire like in live microphones. I guess they still use the plus and minus symbols just to confuse everyone.

[Quasimodem]

Okay, attached is my little diagram of wires, pinout, what I learned (the front right, front left, right rear, and where I am guessing the left rear channel is). Hope this helps people prying into their late model BMW 3ers with standard US stereo.

[VP Electricity]

Originally Posted by Quasimodem

Thanks. I guess I should have figured that out, since in a normal RCA cable the shield is usually the ground (negative in our cars).

It is a bit confusing because when using balanced inputs, one really isn't plus or minus, they both carry signals. If there was a negative wire, it would be a third wire like in live microphones. I guess they still use the plus and minus symbols just to confuse everyone.

It seems to have worked with you

No, they really are (+) and (-).

Technically, an RCA carries an AC signal - centered on 0V, half of the signal is above 0V (positive) and have is below 0V (negative). THAT shouldn't be called "positive", but it is, and NEGATIVE is actually ground.

A balanced signal has two "clamped DC" components - each varies in voltage, but never crosses the 0V line - it's either always positive or always negative. "Ground" is something else. But the positive signal is always positive and the negative signal is always negative.

[VP Electricity]

Here are some pics:

RCA AC signal:



Balanced positive and negative signals:

[Quasimodem]

Originally Posted by VP Electricity

A balanced signal has two "clamped DC" components - each varies in voltage, but never crosses the 0V line - it's either always positive or always negative. "Ground" is something else. But the positive signal is always positive and the negative signal is always negative.

Sounds like interlacing on a TV screen.

And for your entertainment, here is a quickie iphone photo of my secret bracket, I installed today, allowing top mounting of my front mids.

Its not quite finished, but the door panel fits.

[VP Electricity]

OK, now I don't get it...

[Quasimodem]

Originally Posted by VP Electricity

OK, now I don't get it...

That bracket, once I drill a few more holes in it, will allow me to top mount my front mids without putting any screw holes in the door panel. It will allow me to "pull" the speaker from behind with cable ties inserted through the spider structure of the speaker. The driver's side is already installed and I just need to wire it up. More info next weekend, until then, I need to earn money.

[VP Electricity]

Ah, not all the holes are in yet, got it.