Hey guys, I will start by saying I don’t post very much on the site, but I have been reading every forum I can find for the last two days about this install. I have a 2006 Mercedes C230 with an Audio 20 radio. I already have the factory head unit out and I am having a lot of trouble figuring out what I need to properly wire up the new Pioneer AVH-2400NEX double din unit.I have several questions with pictures so hopefully that will clear things up.

1) What harness do I need to adapt the factory harness to the double din??? The metra harness and those used on the forum only seem to have 16 pins and do not adapt the white connector from the factory harness that I have circled in blue. See additional pictures with red writing labeled “new plug” to view harness that appears to adapt the white connector due to the horizontally aligned pins on the top. That area is recessed without any pins on top in the metra or other aftermarket harness such as the one I have attached labeled “adapter harness”. Is that what the adapter harness should look like? Here is a link to where I saw that “plug” or harness that seems to adapt everything, but I have failed to find it for sale. http://www.dvdgpsnav.com/blog/category/mercedes-benz/ (Scroll to 1/2 way down under W204 install after clicking the link)

2) I have been unable to identify if this Audio 20 radio has a factory amplifier. When I researched my vin I only saw “Audio 20 Radio” listed. There isn’t any writing or indication on the speaker panels so I am not sure. If it does have an amplifier, Is there something I need to convert the analog signal from the new double din to a digital signal? A guy on this YouTube video ( ) that I emailed said I needed the Axxess XVSI 9005 NAV. Here is a link. https://axxessinterfaces.com/product/XSVI-9005-NAVThis appears to only bypass the amplifier so does that lead to poor or worse sound quality than factory sound? Also, in the YouTube video he basically just assembled and disassembled the unit. He does not explain the wiring or modifications needed for the double din to work properly, so that is why I am on the forum after relentlessly searching YouTube, the internet, and forums.

3) Can someone please help? I plan to make a YouTube and do a full write up of the wiring in the double din once I know what to do in case others run into this issue
Thanks,
Travis




Factory Harness with strange white connector (circled blue) and orange fiber optic housing (circled red)


View from the back of factory wire harness


Adapter harness from Amazon. Again note recessed or empty pins at the top that will not adapt the white connnector circled in blue from the other picture


Cannot tell if that "new plug" on the left is actually an adapter or just the the other side of the factory connection that goes on the factory head unit. This image is a screenshot from the link in my post. Here is the link again http://www.dvdgpsnav.com/blog/category/mercedes-benz/

 

From what I understand the Audio 20 has an amp in the trunk inside the righthand liner ... however there are two big differences from Audio 10 w/o amp:

1) The communications from the head unit to the amp are via fiber optic, and I have no idea what the audio format is, how many channels, etc.
2) The wiring to the speakers comes from the amp in the trunk, not from the head unit.

Based on the above, your "empty" area in the harness is likely the four pairs of speaker wires that the Audio 20 doesn't have.

That Axxess adapter doesn't look like it handles fiber optic ... these cars use a MOST system so you need to find a MOST adapter for Mercedes (e.g. https://avinusa.com/most-fiber-optic...edes-benz.html). I know little about this other than it looks like these adapters exist, so please do your research and don't take my word for it. But if this is a viable option then you can theoretically get by with only adapters behind the head unit and not having to rewire the speakers.

Enjoy the adventure, please keep us posted on your progress!

Thanks. John

 

First off thanks John!
I appreciate your input regarding the amp and fiber optics and for also attaching that link. Could I just use a fiber optic bypass loop cable like the one in link below or does it need to be integrated/attached to aftermarket head unit?
To clarify the white connector I'm talking about is part of the FACTORY harness. It DOES plug in and there are pins for it on the receiving end of the FACTORY/ STOCK UNIT. I was saying there is NOT a place for it to connect on the aftermarket adapter harness which will be wired to the end of the after market head unit so I dont know if it is important or not.
Any thoughts??
Thanks,
Travis

 

Regarding the fiber loop ... do you have a CD changer in the glove box? On my car the fiber from the radio only went to the CD changer (2' cable in total) and was not part of the bigger MOST circuit in the car ... so I didn't need a bypass cable. But your car may have more devices connected to that particular cable.

I assume the fiber goes to the amp in the trunk ... are you not not planning to use the amp then if you are thinking about bypassing the fiber? I would think the MOST adapters would plug into that cable.

 

I don't believe my fiber optic cable was ever attached to amplifier because I did not see an additional amplifier when I opened the liner in the trunk on the right side.
I found the other end of the fiber optic cable looped up with factory mesh around the connector so I assume I do not have the M.O.ST??? Is that correct?
I also DO NOT have telephone buttons enabled, Navigation, Bluetooth, or CD changer in glove box.

With that being said. Would something like this work? https://www.crutchfield.com/p_249SWR...Interface.html
It says it would allow for retention of steering wheel controls and use of non-digital factory amplifier.

Again, I am still worried about the mystery white connector I have that wont adapt to an aftermarket adapter harness but I am less concerned now that I have the fiber optic issue figured out.

Here are some pics of what I saw in trunk

 

Here's an Audio 20 pinout diagram:



So it looks like you should have the speaker wiring in that harness, and the missing plugs are for telephone and other controls? There is an AWSC adapter that you can buy for this.

 

Got cha! That diagram is super helpful, thanks! It is nice to know I wont be missing any wiring to the speakers. I am going to use the CRUX SWRBM 57 adapter.

What did you think about the fiber optic cable I found in the trunk? Are you pretty confident that I don't have an additional amplifier that uses a digital signal??

 

Wait -- my bad ... I had the Audio 20. It's been a while ... I was thinking that Audio 10 was the base unit on these models and Audio 20 had the upgraded sound system and video ... but I think Audio 10 is the pre-2005 single-DIN units and Audio 20 is our base double-BIN, and COMAND is our upgraded head unit.

That means you should have what I have ... yes the coiled fiber in the trunk is for the cars with the upgraded stereo with amp ... many mfgs install the same wiring harness in their cars for all trim levels to cut costs (i.e. same part on all cars, fewer parts to manufacture) and allow for dealer installed upgrades, so that doesn't surprise me. I'll bet you also have phone hookup cabling under your console compartment.

If your car is like mine, that fiber to the head unit probably just goes to the CD changer in the glove box and nothing else, in which case you can just discard it along with the CD changer.

How does that all sound?

 

Exactly right. I'm not sure if you mean the phone hook up behind the factory unit because I did see and extra connector unattached and nothing within the connector 2 housing of the factory harness, in reference to the diagram you posted . Nothing in center console and no cd changer in glove box! Hey do you know anything about the Crux SWRBM-57 that mentioned??
It is talked about it in this thread BELOW starting at post #15
https://mbworld.org/forums/c-class-w...0-revival.html

Anyway, I ask because I mounted my bluetooth mic near the rearview mirror and routed ot behind the liner and beneath the under side of the dash. It has a 3.5mm plug to go into the double din but that Crux unit also utilizes a 3.5mm plug to help retain steering wheel controls. Could i just get a dual aux adapter like this and plug it into the double din?

 

My z130BT has separate jacks for mic and for external controller, and it looks like yours does too (jack #2 in the diagram I pulled for your head unit) ...



Is this not correct?

-- John

 

Yeah man you were right. Taht is correct. I have wired everything up and my double din is functioning EXCEPT the steering wheel controls!! I used the Crux SWRBM-57 interface and am somewhat confused as to why they are not working. Here is a picture of what i see on the in dash display above the steering wheel. It just says "Audio" with several dashes below it. There are also these three on off buttons on the Crux box (circled in blue below). There are specific instructions on how to position them. 1. ON 2. OFF 3. ON. but it still isnt working.

I thought maybe I had the 3.5 mm jack plugged into ththe wrong place. I have it plugged into a port with "W/R" below it. Which is #2 on the diagram you posted above. When I plugged it into the aux port. and switched to aux mode on unit I then could hear a noise when i pressed the volume button but that was it..

ANY TIPS on getting the steering wheel controls to work??? I thought this unit was supposed to be easy and plug and play for steering wheel controls!!! I am very frustrated because everything else appears to work!!

 

The unit I purchased said it could not display info on the dash screen ... it could only recognize the steering wheel buttons. So what you see on the dash is probably all you're going to get.

As for steering wheel controls -- read the programming instructions for your controller carefully and try it again ... it took me two or three times to get it all to work ... but it's been working now flawlessly for over 5 years.

 

I think I glazed over instructions too quickly. I just noticed the 3.5mm plug the Crux SWRBM-57 uses REQUIRES a 3.5MM to 4 pin adapter!!!!!

Hopefully I can find this adapter within 20 miles and not order on Amazon. I will let you know if this fixes the issue. On a positive note, I popped Star Wars into the new din and put it in drive reverse and it stayed on!! I would never watch it while driving but a cool feature for a passenger on a long trip and worth the $8 microbypass!!

I'm hoping this fixes my issue and I do not have to splice any wires given this isnt indicated on the instructions. I am tired of connecting wires Haha

 

You have two SWC cables, one of them should fit your unit ... in your earlier post you said you had it connected to the #2 jack on the back of the radio ... so it sounds like you have the cable you need.

Your description of your dip switch settings (ON/OFF/ON) is the JVC setting. You have a Pioneer head unit (OFF/ON/ON) ... is that the problem?

 

Hey, got it figured out. Here are some shots from the finished product. Thanks for all your help! Yeah I had to put it in OFF ON ON position which I had already tried but had to do so with key in off position even though it says to only do so for BMWs.

Here is a YouTube video for anyone completing this project on a C230 Mercedes WITHOUT upgraded sound AND WITHOUT FIBER OPTICS in the future. I just explained some things I faced during the install and what I did and also explain the products I used. Hope it helps.



Pioneer loading up


Return of the Jedi playing


With USB cable


Steering wheel controls

 

 

No I could not. It's weird.
Same thing with the telephone display in the gauge cluster although that didn't apply to my vehicle before the install.

 

 

I actually was able to adjust the clock on the mfd