[jc-place]

The following are steps it took to install Ipod aux input on factory Becker 3309 Mercedes head unit (used 1999 - 2002 model year) for free. I believe this is called a tape deck hack since a blank tape has to be put in for the input to work. This method will give you crystal clear digital sound WITHOUT FM modulator interference and you get to keep stock look that no one wants to steal. Also, steering wheel volume controls remain as well as the obsolete CD changer.

**Please proceed at your own risk and make sure you have an extra head unit handy if you don't know what you are doing. If you are familar with mercedes radios, this can be done in less than 20 mins from start to finish.

This head unit actually came out of a 2000 w208 and it is the same as the one in the w210. I also did a hack on my 1998 E320 but it was much easier to figure out since the technology wasn't as small (1996 - 1998 used different head unit) plus it was marked "L" and "R" right on top of the tape unit circuit board.

1) pry off top of unit.

2) remove all screws from bottom of the unit. I believe the thick aluminum amp heat sink/cooler can remain on the back.

3) remove two screws from that attach the face plate then gently pry lever to tape deck door to left as show until it snaps off the brass peg. Look very closely on how the spring is set on the lever and how the lever goes thru the front before removing it. The spring might have to be set back in place. Once off brass peg unsnap clips to release faceplate forward.

4) Now you are ready to remove main board from the base so you can get to the botton to begin soldering. Three solder connections are required A) red (right) B)white (left) and C)ground wire (exposed or black depending on your cable)to ground point. Solder the wires to the two points shown on the board. (ignore the black marker marks, i put those there for my reference). The right and left channels are almost side by side. Next solder the ground wire to the radio chassis or under a screw. Make sure the ground wire is insulated/coverd so it does not touch and short out anything on the board.

5) Blank cassette tape with all its guts removed must be used. If not the ipod plug interface in mentioned in post4 below will get warm. See last picture in series of the gutted cassette tape that is required.

6) Enjoy crystal clear music. I have done this to two of my mercedes that still have factory radios and now I almost never listen to my FM radio.

Link with info BECKER 3309-Mercedes Benz MY98

Please see YOU TUBE DEMO link below:

Let me know if it was easy and worked well for you.

 

[gsmcintyre]

Hey JC. Thanks for the great write up. LOL @ be sure to have a backup head unit! (Yeah, I keep them stacked in my garage.)

I am tired of the muddy sound when using the cassette adapter. I'll try this next weekend. Any chance you have a few more pictures of the bottom of the circuit board better showing the general location of the solder points? The detailed (close in) shot is good, but would be nice not to have to scour the board for that solder pattern.

I think I'll find an old cassette tape and remove the innards for when Ii have my iPhone connected. Theoretically, the cassette deck should still work, right? Not that I ever use it, but you never know.

I'll let you know how it turns out when I get time to try it.

Again, thanks for posting this!!

Cheers -- Greg

 

[Yacht Master]

Great information, A few more pics would not hurt, Hard to see the location of the solder points. Is this the same connection that Becker offers for $100 ? I also see that your cassette is gutted, so I have a question.
Would a cassette adapter (pickup type) with out it's (noisy) tape simulator internals (gears/rubber bands) still work? I was under the impression the tape player needs to "feel"
rotation on one if not both capstans in order to work.

 

[jc-place]

Sorry, my wife took the good camera with her out of town, hence this is why i had time to figure this out without interuption. By the way I have added an update to my mod above.

I had an Ipod interface kit i bought for my 1998 wagon for $11usd on ebay but discovered a CD changer is required for it to work.

Soundgate MBPDAUX1 iPod Aux Input Mercedes Benz 94-98
Soundgate MBPDAUX1 iPod Aux Input Mercedes Benz 94-98 | eBay

So i took the Auxillary plug I just added and plugged it into (audio out plug) on the black box with Ipod connector end and then connected the yellow wire to 12v+ ignition on and black to ground. Very Very surprisingly it actually charges my Iphone 3gs while it plays!!! I just threw away benz harnes adaptor and the big box with the AV cables coming out of it.

This kit might be a very good option if you have a CD changer on 94 -98 model!

In the end, I routed the Ipod cable connector thru center console into the armrest and can pull the plug out 2 1/2 feet so I can rest phone by gear shifter. It's very cool, i can just shake the Iphone to change songs.

On your other questsion, yes it works perfectly with blank tape and the sound is cystal clear digital sound without any wires visible and volume can be steering wheel adjusted. Plus the tape adaptor may not work because LCD pannel must be closed to play. On my 1998 wagon pryed the cover off top and the solder points were clearly marked "L" left and "R" right on the top of tape unit thus it was very easy to figure out compared to the new one (did not even have to remove a screw on the 1998 unit). I made an empty cassette because my daughter kept hitting the eject button causing the tape tray to lift which made it nolonger play. Now i just keep a blank tape in it to fool it. I guess this is why its called a tape hack.

By the way, title should read 1999-2002, sorry my mistake.

 

[mbvis]

Did you test if the cassette player still played with real cassette tapes and produced sound? I still played some old tapes in mine. Even though tapes are obsolete to many people but having something broken in a Mercedes would give owner a bad feeling. It looks to me that two pairs of analog signals (L, R) are "wired-and" unconventionally. Conditioned signals from the magnetic head of the cassette player "wired-and" to the signals coming from an external mp3 player. Such action might damage the cassette player.

 

[jc-place]

Did you test if the cassette player still played with real cassette tapes and produced sound? I still played some old tapes in mine. Even though tapes are obsolete to many people but having something broken in a Mercedes would give owner a bad feeling. It looks to me that two pairs of analog signals (L, R) are "wired-and" unconventionally. Conditioned signals from the magnetic head of the cassette player "wired-and" to the signals coming from an external mp3 player. Such action might damage the cassette player.

:thumbsup: The cassette player works perfectly. Sound qualilty on the cassette player is perfect as it can be for anolog media. I tested every function on the player and everyting worked as if it was untouched :thumbsup: This is also true on my 1996 -1998 hack not shown here.

This is wired directly to sound processing chip (pins 7 and 24), so the Ipod or MP3 music is pure digital and very very high quality crystal clear sound. The chip was so small, so I had to find the contact points on the back of the board to easily soldier contacts.

If you are worried about the cassette player, this post is not for you. About 6 years ago, i converted all of my CDs to MP3 and threw most of the CDs away at that time. I put a SONY Ipod direct control/connect unit in my 1997 E320 about 5 years ago. This SONY unit looks ugly and out of place with its blue glow and onscreen graphics. After discovering this hack, I might buy a used MB unit and utilize the hack on that car as well to get the factory look back.

I will try to add a very short demo video. I will have to take head unit apart again to take better pictures(not sure if I with do this).

Thanks for all of the replies.

 

[gcavy1]

thanks for this write up. This is exactly what I was thinking of doing when I first got my wagon a couple of years ago...I remember thinking, "if I could just tap into the tape player's output to the preamp/amp section, I could bypass the tape heads altogether...probably a circuit-board though, better not mess with it"

I ended up just dremeling out a small notch in the faceplate so I could run a tape adapter with the face plate closed.

I may have to do this though, I really hate the tape "noise" in my music.

So you have an "Iphone" connector on one end that also has 12v going to it? I was also thinking of doing the same thing. Does the Iphone need any buffering/capacitors etc... or does your cable just split off into a straight +/-/ground for power, and a +/- for stereo sound?

 

[jc-place]

The auxillary out of head unit plugs right into the soundgate box and the soundgate plugs right into Iphone (plug and play) . The only reason for adding the 12v to yellow wire and ground to black wire on the soundgate box is so the Iphone 3gs will charge while playing. I still can't believe this supports charging a 3GS, most non-Apple items don't support most newer model apple products.

 

[cobac]

Very cool mod!

Does the tape still spin when you select cassette and use the aux in? Just wondering if that's necessary since the mechanicals on my tape player are kinda loud. Thanks

 

[spicyguy2005]

Thanks JC for sharing the information. I have no experience doing anything like this before. If I am trying to do this modification, the soundgate kit that you mentioned in your post is the one I should get, right?

I checked on the ebay link that you provided, but I don't feel that I know enough to start playing with it. Can you explain a little more on the connection and which wires will be used and which one will not?

Thank you in advance for your help.

 

[Graplr]

Thanks, this is great! I really want to do this.

A couple questions...

1- All I see coming out of the tape deck is the cord that plugs into the headphone jack. This is what you are using to hook it up to your Ipod, correct? If so then I could plug it into any device and get it to play, not just Ipods, correct?

2- I only see two wires in your pics. You mention black and yellow ones. How many do I need JUST to get sound (no charging). How/where do the two wires coming off the board turn into/plug into the headphone jack wires?

Thanks!
Ryan

 

[C_R]

When can I send you my radio?:thumbsup:

 

[jc-place]

Video Added to Post#1 !!!

Thanks, this is great! I really want to do this.

A couple questions...

1- All I see coming out of the tape deck is the cord that plugs into the headphone jack. This is what you are using to hook it up to your Ipod, correct? If so then I could plug it into any device and get it to play, not just Ipods, correct?

2- I only see two wires in your pics. You mention black and yellow ones. How many do I need JUST to get sound (no charging). How/where do the two wires coming off the board turn into/plug into the headphone jack wires?

Thanks!
Ryan

I added a video demo that should answer all questions (Video is worth endless words).​

I made an edit to make the the first post more clear on the wiring.

1) yes the male end auxillary line you just soldiered on the board can be plugged into any auxillary player such as generic MP3 players, CD player etc. Follow the instructions in first post for basic aux out line install. It only involes THREE basic wires: Left (white) Right (Red) and ground (black or bare copper) wire on aux cable with male end.

The Yellow and Black wire only refer to the Ipod interface cable addon (soundgate module) in my Post#4 (see details in post#4 if interested). This addon is not need to play music but is very cool if you have an Apple product. You can just plug the auxillary line you added into the headphone jack on top of the Ipod if you don't care about the the cool ipod interface cable.

:thumbsup:

 

[Graplr]

jc-place- Thanks so much for your willingness to help!

I guess the thing I can't wrap my head around is what type of cord will I be using? I see the kit link but I don't want an Ipod plug just an auxiliary cord to be plugged into any generic audio device headphone jack. So what type of cord can I use? Can I just use any pair of headphones and cut off the ear buds and solder them in the correct location? If so I'm confused on where the third (ground) wire comes into play. If I can't use headphones then where would I get the wire needed to do this mod?

 

[mbvis]

Thanks to OP for the hack. I'm doing mine on the '99 W210, but not finished yet to verify if it works. I'm at the point to solder the wires. The joints that the OP pointed are too small to touch. Tracing up the board, there are two better joints for soldering. They're like 10 times larger for any solder gun's tip to touch. They're confirmed with an ohmmeter.
Tiny solder joints may break out over time with car vibration then causes short circuit. I suggest taping the wires down onto the board after soldering.

 

[mbvis]

My bad. Please ignore the previous picture.
The solder joints are reversed as shown in the new picture.
The hack/mod works for '99 w210. The only strange thing is with playing a particular cassette tape, I can hear both the mp3 player and the tape on side 2. On side 1, only the mp3 player is heard. I guess playing a blank tape should work for both sides.
Thanks to the OP for ... making me busy. My '01 already got the Aux in the glove box. I got 1 more W210 to do then my folks called upon the news, "Hey, we'll bring our cars over this weekend ..." Did you hear that? "our cars".
My order from Radioshack has just arrived, too. Three JVC HD radio adapters. Ahhhhhhhhhhh!

 

[Graplr]

mbvis,
Nice work. Did you put a ground wire on? What type of cord did you use? It appears you only made two solders with no ground.

I'm having trouble conceptualizing how the ground wire attaches to the auxiliary cord.

 

[mbvis]

The OP must have done it with a much better way. I think he's not going to open up his work again to show it in details. LOL.
Before making it permanent, I used a "3.5mm Stereo Plug/2 RCA Female Jack Cable" for ease of testing. There are 2 screws on the rear top to hold the heat sink. Use one of them to hold the ground wire (unscrew a little bit then loop the wire then tighten).
Your head unit may be different. Mine got a hole in the back to route the 2 signals out.
By the way, I fuond out that my cassette tape's side 2 was recorded "loud", that's why I could hear mixed music from both the mp3 player and the tape. A blank tape fixed all that. It's amazing that the cassette player's signal driver didn't get burned when the wires are wired-anded.

 

[Graplr]

mbvis,
Thanks for the help. I see one end of the ground on a screw at the back of the head unit but where does the other end go? I can't quite see in the pic but it appears that it is just hanging loose. I guess I'm still not quite clear on the purpose of the ground wire/what it ties in to since the other wire you are using to plug into the audio device only has two leads (L and R).

 

[mbvis]

The ground wire was actually "taped" to the ground contact on the red RCA plug.
These should explain it.