What's the 6 pin plug on the tuner of my BE1432 for? - PeachParts Mercedes-Benz Forum

compu_85 · #1 01-24-2009, 08:55 PM

I'm looking into adding an aux in to the BE1432 system in my SDL. What I've come up with so far:

-I have an Alpine 6 disk changer with a converter unit on the back to make it "talk" Becker. I know which pins on the output from the CD changer are audio, I could interrupt them there. But then I loose the place I was at on the CD in the changer when I go to the aux in. I also have a working Silverstone 10 disk, and would rather use this changer because of its extra capacity.

-I've taken apart a spare tuner unit. It's kind of interesting inside: There are removable modules for each function. One does the RF in from the antenna and FM decoding, one does the AM decoding, one has the CPU and ROM on it, and one has the audio processing chip that switches between inputs and does the bass / treble / balance / fade control. One chip in this unit, the TDA7300 does all this work.

This chip has 4 stereo + one mono inputs, and is controlled by the CPU. Looking at the board it seems like only three are used: Probably for AM (interesting because the AM decoder chip can do stereo according to its datasheet), FM, and CD. My thought here is I could figure out which input is from the FM section, desolder and socket the chip, and then interrupt the signal there. Or, if I was really tricky, I would use one of the unused inputs and figure out the control system for the chip and make it switch to that input... but that would probably piss off the CPU in the radio.

-There's also a 6 pin din connector on the CPU module, right above the 8 pin din connector for the "data bus" cable. Looking at the traces some of the pins on this are simply linked to the data bus connector.

Does anyone know what this 6 pin connector is for? Or does anyone have a pinout for the "data bus" cable?

I have a pinout for the cable that goes between the alpine changer and the becker converter unit (Yes, it's the same 8 Pin cable as a standard alpine m-bus system, but they moved some of the pins around... they switched power and ground around among other things). It's saved on another computer and I'll post it later.

Thanks,

-Jason

compu_85 · #2 01-24-2009, 09:17 PM

Picture time!

From Left to Right: AM Decoder, FM Decoder, Audio Processor, CPU / ROM

Top to bottom: FM Decoder, AM Decoder

CPU / ROM, Audio Processor

compu_85 · #3 01-24-2009, 09:18 PM

Insides of the Headunit:

-J

compu_85 · #4 02-01-2009, 08:30 PM

No one knows

Peter Guenther · #5 02-03-2009, 08:09 AM

this will ofer some info
http://www.beckerautosound.com/1432-1991/index.html

compu_85 · #6 02-05-2009, 12:05 AM

Yup, I've already been through their website. No schematics or pinouts of the data bus cable are posted.

-Jason

cyberdyne · #7 11-11-2012, 04:09 AM

I hate to be "that guy" and bump an antique thread but I could find no other posts on the topic.

I am in the same boat as the OP. My 8 pin DIN cable has been damaged at both ends by a poor installation of an aftermarket head unit by the previous owner.

It seems like much less work to repair the DIN cable at both ends rather than running a new cable. I have sourced new 8 pin DIN plugs, but I need a pin out or wiring diagram to go from when repairing. I managed to find another DIN cable end but after stripping it down the wires are different colours.

Any help would be appreciated!

compu_85 · #8 01-25-2014, 09:22 AM

Some more 1432 tidbits:

Radio station memory is stored in the tuner.

However the audio is routed into the tuner from the tape deck and CD changer it seems to come in on the same input as the left channel of both quit working on my car. Thankfully I had a spare tuner and that solved the problem

AM reception sucks with the new tuner though. I might swap the AM module out with the one from my original unit.

-J