Cryptnotic

I am looking for info on the pins on the back
of the Mercedes radio in the C230K (the
stock one, not Command). There is a big
cluster of wires going into three stacked
block connectors. I assume that these are all
of the power, ground, accessory, and speaker
connections, but also the steering wheel control
signals. I know the steering wheel controls
are not on the optical bus since they still
work when the optical cable is disconnected.

There are also two coaxial connectors, one large
one that is the radio antenna, and one small one
which I assume must be for the cellular phone
option.



Thanks,

Cryptnotic

Cryptnotic

I've got another question. Where can I get
a wiring harness adapter for an aftermarket
radio? I'd prefer not to cut into the cable
block and screw it up for when I want to
put the stock unit back in.

Thanks,


Cryptnotic

Cryptnotic

By the way, the whole point of this exercise
is to take my stock head unit and CD changer
out and set it up on a bench with an oscilloscope
and a logic analyzer and figure out a way
to interface a Phatnoise Car Audio System
(http://www.phatnoise.com/) to the optical
bus without using a cheezy RF modulator.

In the meantime, before I get that working,
I want to put in an aftermarket radio that
is Phatnoise Compatible.


Cryptnotic

(I work for Phatnoise, but this isn't an official
Phatnoise project).

renncpe

Hi,
I have stock MB head unit sitting under my desk, took it out of my 2002 C230K Coupe. If you need one to play with on the bench I can send it out to you. I have some other questions for you. Do you have an e-mail.

Randy

Flashman

Can you take a picture of the back of the stock head unit?

renncpe

Sure I'll get it up later today.
Randy

Cryptnotic

I've put up a PDF of what I have figured out of the pinouts on the back of the stock radio/wiring harness:

http://www.tokidoki.net/~crypt/mercedes_radio.pdf

It also includes information on the Becker Mexico pinouts (from a Porche Becker radio).
Interestingly, some things that are on the Becker Mexico radio are not connected on the Becker Mercedes.

If anyone has more information, please share.
Thanks.

wysocki

Doh! The link is dead! I need to find accessory power source (on when key is on) in wiring behind HU in 2002 c230 coupe. Anyone know where it went?

sura

Is this the diagram you're looking for?
Mercedes pin outs

wysocki

I need a 12v+ trigger when the ignition is ON. It looks like A7 is my best bet. Thanks for the diagram!!!!

EDIT: Oops, it looks like that's only for the Becker Mexico version not the Mercedes. Where can I find a 12v switched in the front console area (or under the passenger dash)????

scorchie

Umm, A7 is ignition power, which goes IN to the head unit. You want something coming out to trigger something else (like an amplifier etc.)?

Coming out would be accessory trigger.

On the W203 there's no KL15 (the ignition power).

Here's the pinout listing I've created.

W203 AUDIO 10/10CD/30/30APS PINOUT

A CONNECTOR (BOTTOM)

1 N/C
2 DIAG
3 PHONE MUTE
4 KL30 (DAUERPLUS)
5 ACCESSORY
6 N/C
7 N/C
8 KL31 (MASSE)

B CONNECTOR (MIDDLE - 8 PINS - NOT USED WITH BOSE)

1 SPRECHER RH+
2 SPRECHER RH-
3 SPRECHER RV+
4 SPRECHER RV-
5 SPRECHER LV+
6 SPRECHER LV-
7 SPRECHER LH+
8 SPRECHER LH-

C CONNECTOR (TOP - 10 PINS)

1 CAN H
2 CAN L
3 N/C
4 D2B WAKEUP
5 KL30 (DAUERPLUS)
6 KL31 (MASSE)
7 N/C
8 N/C
9 N/C
10 N/C

wysocki

Still no luck. I think the problem is that I've actually REMOVED the head unit and just want to use the wiring harness to tap into a 12v source that's active only when the key is on. I've put a computer in my car replacing the HU and its power supply needs a trigger signal to power up on. It then sends a trigger signal out to the amps once the computer's up and running. A guy at my local car audio shop says to put a jumper across A3-A4-A5 but that didn't work either.

Without anything connected to the HU cables, I see 12v on pin A5 but it's always hot. I can't find any pins that go to 12v when the key is switched. If these wires don't work, maybe I can find where the cigarette lighter gets its feed from (it goes on with the key). I have the front panels off around the HU but I can't figure out how to get the ashtray or the console panel around the shift lever off to be able to locate the cigarette lighter wires. Any further ideas for where I can find this switched 12v signal?

scorchie

This has been discussed at length in the forums. Please use the search feature to find out more.

If you look at the pinouts I posted, you'd see there is no switched ignition power. The back of the lighter is the place I've recommended for a long time (here at mbworld!).

Hope you find the info you need!

-s-

Lalee

Looked up pin diagram from post3016786
Two types are listed: Mercedes and Becker Mexico.

My car is without bose system, and I don't see wire connected to pin A7 - which is supposed to be the switched plus for Becker Mexico,

So seems my system is Mercedes, so in this case, which wire should be used in place of A7 for switched plus.