Audio 20 Pinout Diagram

[E55BOF]

The car is a 2008 CLK (W209) Convertible. I have removed the head unit - basic poverty spec Audio 20, single CD, no MOST, no CD changer, no Nav, steering wheel volume control, and that's it. The only surprise was two Fakra aerial connectors, not one; turns out the 'vert has two radio aerials as standard, one front one rear, and of course, no roof aerial.

Does anybody have a pinout diagram for the Audio 20 so I can work out what goes where on the (NOS) Blaupunkt Stockholm 370 DAB BT single DIN head unit I'm fitting?

 

[E55BOF]

Audio 20 model no. MF2740, if that helps?

 

[E55BOF]

STOP PRESS: Found what I wanted.

 

[clk320x]

STOP PRESS: Found what I wanted.

Worth sharing on here for anyone who has the same doubt in future?

 

[E55BOF]

Good point; here's the link to the info:

Mercedes-Benz, Smart OEM Car audio harness pinouts diagrams @ pinoutguide.com

It's hosted by a Russian site, but I don't think it's some form of KGB/FSB dezinformatsiya... Though come to think of it, I wouldn't mind being caught in a honey trap...

 

[Gollom]

Good point; here's the link to the info:

Mercedes-Benz, Smart OEM Car audio harness pinouts diagrams @ pinoutguide.com

It's hosted by a Russian site, but I don't think it's some form of KGB/FSB dezinformatsiya... Though come to think of it, I wouldn't mind being caught in a honey trap...

Hopefully, not the kind that involves MPs and is currently in the press......

 

[E55BOF]

I have no political ambitions. Come and get me, Darling...

 

[richard]

Use the black fakra for an aftermarket one, the mustard one is a special diverse antenna.

 

[E55BOF]

Thank you; I will.

What is the mustard one actually for, though? And is the mustard one the front or the rear aerial connector? (I ask because I'm curious, not because I'm going to ignore your advice).

 

[SpikyMikey]

Thank you; I will.

What is the mustard one actually for, though? And is the mustard one the front or the rear aerial connector? (I ask because I'm curious, not because I'm going to ignore your advice).

Your original head unit processes the signals from more than one antenna ("Diversity"), which is why you have 2 Fakra connectors.

 

[E55BOF]

Thank you for that. I assume, then, that two signal inputs down one aerial feed would interfere with each other, despite the fact that it was one and the same signal when it was transmitted? A layman (me) would have thought (and I did) that having two signal inputs would simply give a stronger signal.

 

[Stratman]

A diversity aerial sytem is used to help improve reception when in areas of poor reception, such as among city centre tower blocks or in hilly areas. The radio can receive reflected instances of the same signal, causing interference. The radio uses signals from more than one aerial to minimise this interference by combining the signals and electronically choosing the best bits in real time.

 

[SpikyMikey]

Thank you for that. I assume, then, that two signal inputs down one aerial feed would interfere with each other, despite the fact that it was one and the same signal when it was transmitted?

As Stratman says, the clever bit happens at the head unit, which doesn't just receive the signals from the aerials, it actually processes them.. As the aftermarket unit doesn't do this, yes you're right, feeding two sets of antenna signals into it won't necessarily give you 2 times better reception.

 

[E55BOF]

As the aftermarket unit doesn't do this, yes you're right, feeding two sets of antenna signals into it won't necessarily give you 2 times better reception.

In fact, it could indeed generate interference if there are reflected signals around. Thank you, gentlemen.

 

[Trickythemerc]

The aftermarket unit will need two signals FM and DAB.

 

[E55BOF]

Yes, I have the DAB aerial to fit.

 

[Trickythemerc]

Where are you planning to fit it ? Windscreen stick on job.

 

[E55BOF]

Have to be windscreen; no roof aerial on a convertible. At least it will be easier than dropping the roof lining.