: 1989-1991 Bose Gold with CD questions



wws944
07-19-13, 08:22 PM
Hi all,

My first posting here, though my extended family has owned many Cadillacs over the past 60+ years.

I recently picked up a Bose Gold head unit w/CD player from a 1989 Seville. Believe it or not, the CD player actually works! However the radio portion is intermittant. Sometimes it works, and sometimes it doesn't. And when working, it may work for about 1/2 hour and then it dies. Both AM and FM bands are affected. I can hear the bandwidth change when I press the AM ST (AM Stereo) button - so I am thinking the issue is up near the antenna connection in the CDM box. Maybe a cold solder...

So my questions are these:

1.) Does anyone know of an on-line source for the schematics for this unit? I have some older, 1987/1988-ish Delco docs for E-bodies, but they don't cover the CDM box in this unit.

2.) Could someone with a FSM for '89-'91 lookup, or better yet scan, the page showing the connections to this unit? The 20-pin plug on the back of the CDM box is standard GM-Bose. So what I am really after are the pinouts for the 'extra' 7-pin connector which is below the CDM box.

3.) Does anyone have the 1990 or 1991 version of this head unit? I am curious if the AM section stops tuning at 1620 khz, as the 1989 version does, or if GM extended the upper range to 1720 khz in '90 and/or '91?

Thanks!

No one has a 89, 90, or 91 Eldo/Seville Factory Service Manual? Or this head unit installed in their car?

I am trying to resurrect this unit from a 1989 Seville - which is the CD player version of the Bose Gold head unit. I was wondering if someone with a 1989, 1990, or 1991 Factory Service Manual could look up the wiring for it?

The main 20 pin connector on the back of the CDM box is common to many GM vehicles of the era. What I am really after is the wiring of the additional 7-pin (only 5 are used) connector on the lower portion of the rear of the unit.

Can someone please help with this?

EldoRedo
08-01-13, 10:00 PM
I responded to your other post on this subject (Please do not double-post) with the information below. The Service Manual does not give AM or FM frequency ranges for any of the radios.


Not sure if this is what you're looking for, but I show five connections to the radio as follows:

Brown: VF 16V power input
Purple/yellow: VF dimming input
Yellow: memory power
Brown/white: power input
Gray: panel light

wws944
09-14-13, 11:50 AM
EldoRedo: Thanks so much for the information. And sorry about the 'double posting'.

This Bose Gold CD player must have been a fairly rare option. I occasionally visit the local Pick-N-Pull yards, and have only seen a couple of them over the years.

I have been experimenting with it via 12v power supply and running through a home audio system. It actually sounds pretty good - when it works...

wws944
10-11-13, 09:16 PM
Update: I found a second one of these - this time from a '91 Seville. So for the archives, the answer to question #3 in my original post is that even in '91 the AM only goes up to 1620 khz.

As expected with units this age, the CD player won't accept CDs. By swapping the CDM boxes between the two, I now have one that works reasonably well.

wws944
10-19-13, 11:14 AM
...Not sure if this is what you're looking for, but I show five connections to the radio as follows:

Brown: VF 16V power input
Purple/yellow: VF dimming input
Yellow: memory power
Brown/white: power input
Gray: panel light

It seems the above are the normal power wires that plug into the modular CDM box. The wires I am curious about are on the connector that plugs into the main chassis below the CDM box. It is a 7-pin socket, but on the car side, there is only a 5-pin plug. The wires are:

pin 1: black (one would think ground, but there is no continuity to the chassis)
pin 3: purple/yellow
pin 4: grey
pin 5: brown

Internally, pin 7 is also hooked up. Maybe for factory testing?

So if anyone has a '89/'90/'91 FSM, do the above connections show up?

It is also interesting that although the outside appearances are identical, there are actually some significant internal differences between the '89 and the '91 CDM boxes. The '89 CDM box has a main board with several daughter boards. The '91 CDM box is a single board design with much lower parts count. The '91 CDM box is actually identical (including part nos) to the CDM box in my '90 Buick Riviera Bose cassette head unit. One audible difference between the '89 and the '90/'91 CDMs is that when tuning around on AM, and when pressing the "AM ST" (AM Stereo) switch, on the '89 box one can clearly hear the two different bandwidths - even on background noise. This doesn't happen with either the '90 and '91 boxes. Not sure if it is supposed to be this way, or is part of the broken-ness of my '89 CDM box.

On the main chassis, there is a board that is visible under the CD player in the '89 that is not there in the '91. So lower parts count there as well.

wws944
10-30-13, 12:54 AM
Update: I found a second one of these - this time from a '91 Seville. So for the archives, the answer to question #3 in my original post is that even in '91 the AM only goes up to 1620 khz.

One final post, since this thread doesn't seem to be garnering much interest. :(

I picked up a Bose CDM box from a '95 Seville last weekend. From '92 to '95, the Seville/Eldorado Bose head unit had both tape and CD drives in it, so GM relocated the CDM box to the trunk. On the '95, it is mounted next to the power antenna.

The '95 CDM box works great in both the '89 and '91 chassis. Interestingly, the '91/'95 combination now tunes AM up to 1710 khz. But the '89/'95 combo continues to only tune up to 1620 khz. It would be mildly interesting to know if the '90 version of the unit can tune to 1710 khz with the '95 CDM box. A visual difference between the '89 and '91 front panels is that the '89 says "Auto DNR" on the front whereas the '91 does not. I found a photo online of a '90 version and like the '91, does not say "Auto DNR" on it. So maybe with the '95 CDM box it would tune up to 1710 as well?

In '96, Cadillac switched to a new generation of stereos. So that ended any interchange with prior year models.

STS_Seville_Hunter
11-02-13, 03:32 AM
I'm interested... what's a cdm?

wws944
11-05-13, 10:24 AM
I'm interested... what's a cdm?

It is the interchangable modular box, used in a lot of late-80s/early-90s GM vehicles, that is either plugged into the top of the main chassis or remotely (e.g., in the trunk.) It contains the audio and radio circuitry. Measures about 8"x4"x1.5". Most have power amps for speakers built in, but the Bose versions have line-level outputs for the external power amps.

STS_Seville_Hunter
11-09-13, 02:47 PM
Is it inside the actual stereo in these early Bose systems? I have w complete '93 set up u want to install in my '91