I want to remove the standard Bose CD player and replace it with a 12 changer FM system. Should be a piece of cake, right? Wrong, I think. I disconnected the CD player this morning and no radio, no cassette. The unit powers up and when switched to radio, operates the power antenna. This scenario appears to be similar to some problems encountered by others when attempting to replace the Bose receiver or receiver/cd system. My problem however does not appear to have a similar solution since I am not deleting the Bose head unit and the adapter would be unuseable.


I can easily add the 12 changer FM system without removing the CD player but I REALLY only want to get rid of the stock Bose CD player. I have just spent about 25 hours fabricating a really nice (professional level custom) 1/2 DIN panel that houses my new Nordskog digital coolant temp gauge, my cd changer control unit, a mini dpdt switch for fan mod control, a 5 pin din receptacle for my PFC Commander, and two 9 pin serial ports for datalogit and wide-band outputs. I really don't want to go through that again if I can avoid it.

I appreciate any help anyone can give.

 

Does anyone have the Bose system without the optional CD player?

 

The Bose system always had the 1-CD-player!

 

Me again.

It's strange that your total stereo system keeps quiet when you remove the CD-player.
As far as I know both the Bose and the standard head unit are the same (except the Bose printing ;->). And the standard works also without the CD-player (but it can handle one).
The 13 pin round DIN connector has Line INs and OUTs.
Maybe you have to connect the OUTs with the INs and so loop the signal in again. But I'm not sure.
Can you do a setup at the headunit where you turn on/off the external plug?
It's really a strange thing.
Tobias

 

Tobias

Thanks for the responses.

Yup
When the CD player is disconnected there is no signal/power getting to the amps. Everything else works though (antenna, power, receiver etc).

According to a premium stereo intaller certain BMWs and others with Bose systems did the same thing. In the case of BMW, there was a special DIN plug that plugged into the same spot that the CD player plugged into that solved the problem.

The reason for my original question is twofold.

1. The original parts fiche for the 94 shows that the receiver part of the Bose system is different for the glass sunroof model (mine) than it is for the metal or no sunroof models and that the CD player was optional on the glass sunroof model. The fiche shows no available BMW-like DIN plug.

2. I was wondering if someone had a system without the optional CD, if there was a plug (like the BMW one) that was inserted in the CD female DIN port.

Although I have all the original wiring diagrams, I am not that well versed on reading them. Your statement that there is a "line in" and "line out" pinout is very interesting and your solution makes sense. I will look into the diagrams and see if this could be the problem although, I was guessing however that, because the amps are powered, it would be a "power" rather than "signal" problem the "looping" idea may solve that.

My only concern in just hooking up a loop to test it is that there may be some filter, relay, or resistor in the CD that protects the head unit from a raw signal/power input.

Please let me know anything else you are thinking on this problem.

Regards
Jeff

 

Hi Jeff,

Amps should be on, because they get their switch on signal from the 12-pin Mazda connector.
Maybe really the signal thing. But that is also strange.
I do know that the German non Bose and non CD headunit have the same round 13 pin DIN plugs (what you call BMW like what it is not I guess). And of course the German headunits work fine without CD-deck that was not available (only a 6 CD-changer, that's why they have that plug).
Some of the 13 pin are system control switches. But there is nowhere discribed how it really works.

I will make a (English!) overview of all I know about the factory sound systems. Of course I do not know the special US things. So far I thought that only the Touring models had Bose with CD and all others had no CD-Player. But might be that the 1-CD-Player was an option to non Bose systems. In Germany you only could buy the 6-CD-changer. But I guess the 1-CD should work also if you could get one here.
I will post a message in this forum when I finished my FD audio site. I hope I can do that this week.

Unfortunately I can't test how the 13 pin plug works because my FD had an aftermarket Cd-headunit when I bought it.
If some of you US boys have one spare, feel free to send it to me. ;-)
There has also to be the possibility to do a Line-In and so connect all other sources by stereo plug or RCA to the factory system.

Kind regards,
Tobias

http://www.tobias-albert.de/

 

Me again.

Might also be that there are "dead end" connectors in the 13-pin plug of all non-CD units. Amybe that loops the signals thru or switches the control 12Vs proper.
I also have no idea what a line out in that connector is for.
I can't check it because I do not have one as said above.
But I guess not because neither in the German, nor in the US workshop manual the is such a thing mentioned.

Please let me know, what different types of audio systems where available for the different RX-7s as standard or add-on.
Also some copies of your fiches would help me much to help you. Just send them by email.

Cheers,
Tobias

 

...Again me again...

hi Jeff,

you said that the fiche show no round 13-pin connector.
What connector does your CD-player have? It should be the 13 pin thing, not?

The only difference I noticed between the bose(cd)headunit and the standards I could find when reading the workshop manuals: Pin 7 of the 12-pin Mazda connector is GROUND at bose, standard is n/c.
But that should not be the reason.

Hope that you can give me some US material to sove that strange problem.

Kind regards,
Tobias

 

The factory wiring and body electrics manuals show 1 unit (without CD) and the 2 unit (for optional CD in the touring model) are externally identical complete with 13 pin plugs

This is my problem--the wiring diagrams show what is going on in the vehicle wiring, but not inside the receiver and CD unit.

That is my understanding also but the fiche identifies the one with the CD player as being the one with a glass sunroof.


I look forward to viewing it

Anything you can think of is appreciated


BTW where are you in relation to Westfalia. My wife has relative in Heullhorst.

Best Regards

Jeff

 

In Germany only one version of the FD was available.
No options. Waskind of mixture of R1 and touring. With 2nd oil cooler, strut bars, spoiler, leather seats, A/C, cruise control, sun roof...
It's a metal sunroof. So far I even didn't know that Mazda produced a glass sunroof.

I live in Bavaria. Some kilometers far from Westfalen. ;-)

I guess the fiche shows bullshit or is not the accurate like the Workshop manual.

Yes you're right, it really would be fine knowing what that system control lines are handled inside the CD-player. Please let me know when you found out something.

But when connecting the CD-player again, everting's fine, right? Not that only a fuse said goodbye.

When getting rid of your CD player, you can send it to me. I will pay all the shipping costs. ;-)

Kind regards,
Tobias

 

Hi Jeff,

I guess I found something:

I did not read the page so far (where's my big dic.?) but pictures seem to solve our problem.
Seems non-CD-player units have a OEM short plug.

You only have to search persistent...

Read:
http://www.miata.net/garage/sony_cd.html

See you,
Tobias

 

Tobias

What a great find. Now I will get a Miata worshop manual and find out what the pinouts are for. Once I learn that, it should be easy to figure out what pinouts to jumper across.


Thanks and I will keep the thread updated.


Take Care

Jeff

 

Thanks to Tobias I remembered seeing something somewhere and tried another search. Finally Google sent me here:

++++++++++++++++++++++++++++++++++++++++

http://www.scuderiaciriani.com/rx7/stereo_upgrade.html

Date: Sun, 19 Mar 2000 16:10:42 -0800
From: Azeem Raja (ARaja@KestrelSolutions.com)
Just some obscure info if you ever want to use your Bose system without a CD player, meaning just the radio.
The CD player is wired in 'series' with the radio... so if you remove it, the radio stops working. To get just the radio working, requires a 'jumper plug' which connects the signal paths together, as if the CD-player was there.
The dealer is supposed to have this part, but the dealers in my area were completely clueless (the plug is not on the parts microfiche).
So I built one:
Cut the connector off the CD player (with a few inches of wire) It will be possible to reconnect the wires to reserve this. Do not bother going into the CD player, the wires are soldered to the circuit board.

Strip and short the wires so the following pins on the connector get shorted: Look at the connector, find the "key" to align the connector. Under the "key" are 3 rows of 4 pins, followed by 1 single pin. On the 4-pin row right under the key, short the 2 outer pins to the pins right next to them, like so:
Keyway
X----X X----X
X X X X
X X X X
X
(Figure courtesy of: Steve Stover - View with fixed width font)

Use ample amounts of electrical tape and reinsert 'plug' into back of radio.

Finally: You DO NOT need to take the Speedo/tach console out to take the radio/CD player out!
++++++++++++++++++++++++++++++++++++++++

I have a few more place to go to confirm this but it looks like this could be the answer.

Jeff

 

Hi Jeff,

yes that's our solution. Meanwhile I read the miata thing. Don't ask me why the signal comes out from the head unit and goes in agian, but that was your problem.

Do not trust the scuderia link fully.
E.g. the Bose system has also high level outs.

Do you not need your CD-player now?

Well, I do know what pin (of the 13 din) has what name/function. But not how it has to be connected to do whatever.

Well stay in touch.
Tobias