This one took me a long, long time to research, so I figured I'd try to help folks out by writing out my story.
What I started with -----------
I have a 1992 500e. That means it came with a "multi piece" system called the Becker 1432. It is easy to google for pictures of that deck, but this is the system used in all 1992 and 1993 (pre-facelift) Mercedes e-class 500e's. In 1994 they swapped to the Becker 1492 unit, which was much better. If you have a 1492, stop reading this post, because there are tons of options for you.
However, if you, like me, have a Becker 1432, you know a few things...
1.) It usually sounds like hell.
2.) If it has a CD changer, it has a Becker 980. This is a 10CD setup, and is a nightmare. Mine worked when I got the car, but never very well. After a while, it decided to stop working. I went so far as to take it apart and figure it out (turns out that the culprit is a bad plastic gear design, which makes all sorts of problems, and isn't really fixable.
Anyway, most people (including Becker) will tell you some variation of the following:
"Who uses CD anyways?"
"I like to listen to the engine!"
"I use a FM modulator for either an iPod or a changer"
"Trash all that Mercedes junk, and put in some rad ICE!"
"Skip the changer, and send the head unit in to Becker and they'll install a AUX input, and then just hook your ipod up, and you are set!"
Well, I didn't really like any of those answers much. But I had bad FM reception, and was running out of working cassettes from the 80's.
So first, I decided to send my head unit in to Becker for servicing, and adding an AUX.
How to Send in your Head Unit to Becker-----
Firstly, go to this website:
That's the Becker site. And yes, it looks like the type of site that you have your 9 year old son design the first time he has seen HTML. Terrible.
But I digress.
Basically, you take the headunit out of the car, and in my case, I took the FM tuner out of the trunk as well.
You box them up, and send them to Becker (no need to call in advance... which is weird), and include a note in the box that says what you want done, and a phone number and address for you.
They will call you with an estimate, and then after a while, call you back and tell you it is done, and extract payment from you.
In my case (I had the Headunit serviced, an AUX input added, and had the FM tuner rebuilt) it was a little less than 400 bucks.
Fair enough. The folks at Becker were really nice, by the way, when I talked to them on the phone.
That worked really well for me. I enjoy my iPhone tunes in the car, and it works very well. I wired the whole thing into my center rolltop, and it works great.
But still... the CD player.... Grrrr...
What DOES NOT work for the CD player (Becker 980)---------
In my quest to get that thing working, I tried a few things:
1.) Buy more of them...
I bought two other Becker 980 units on eBay. One of them was advertised as working, but was jacked up (there were broken gear parts in the box) when it arrived... (I got a refund, and the guys was cool, btw). The other I bought as a spare, thinking I could make one good one out of two... A few hours messing with it, and I determined that without access to new (not brittle) white plastic gears there was no way I was fixing it...
2.) I called Becker. They said that they USED to fix those things, but the guy said they basically refuse to fix them now. He said that the 980 was a total POS even when new, and it skipped so much when new, they couldn't run them in the SL cars (more on this later!). He said they used to rebuild them, but they only did it in the winter when they were bored, and they charged a ton for it, because it was a terrible job, and about half the time, they broke again shipping things back to the customer.... Grrrrr..
3.) I did a bunch of reading, thinking there might have been a later version of the 980...
I found this:
I thought HA! The Becker 2630! That will work! So I waited, and found one (new in the box) on eBay. It does indeed have the same 10 disc cassette, but it does NOT work in our cars. At all.... It is a completely different setup, and there is no way it will work...
Sigh... So eliminate that stuff.
What works, and what you need--------------
In reading, and looking through wiring diagrams, I noticed that the R129 chassis seemed to have some other type of CD changer, and in order to make it work, they ran a thing called an MX3192.
It is basically a little box that has a few inputs, and some weird wiring sticking out of it...
Looks like this (In this picture it is sitting on top of the CD changer):
So you need to find one of those.
And then you need to find an Alpine CHM-S620. This was a LOT easier to find, and they are all over eBay. I bought one new in box (or maybe used in box, but it had all the parts... so here are some pictures with bar codes to help)
Note that it just has ONE input and output... See the cable sticking out below:
So basically, to get this to work, you unplug the Becker 980, and insert the connections as follows (It is hard to describe in words, so I diagrammed some pictures):
See next post, as this one is getting loooong