Radio- Why not quality aftermarket?

Linus Toy linust at
Tue Dec 17 16:03:08 EST 2002

At 02:46 PM 12/17/2002 , Brett Dikeman wrote:
>At 2:05 PM -0800 12/17/02, Linus Toy wrote:
>>Just beware that the stock Bose speakers are common-grounded.
>This bears further explanation.
>None of the modules are grounded on the speaker-side to the chassis.
>None.  An entirely separate set of screws and mounts are used in the rear
>units, for example.  The fronts are in a completely plastic
>enclosure(there are metal inserts for structural purposes in many of the
>mounting holes, but they're not connected to anything.)


>Each amp has power, ground, signal +, signal -.  All signal wires go
>straight back to the head unit, and the signal -'s are NOT tied
>together.  If you pull ot the radio, you'll find eight wires, not 5.

This is where we differ...see below

>Further, they're not tied to ground.  I do not recall if the grounds all
>run to a common point, or if they utilize 'convenient' chassis grounds
>near their physical locations.  Power is of course central from the relay
>in the aux relay panel(relay is tripped from the radio.)
>I believe SOME Bose systems utilize a common signal negative, which is
>what I think you're referring to.

Yes.  My head unit had, for speaker purposes, 5 wires.  LF+, RF+, LR+, RR+,
and a single - connection.  The four - wires were crimped.  Since we may be
be talking about different head units, mine has the following markings:

on the right side of the radio:
Blaupunkt Bosch Gruppe
7 648 896 180/181

Delta US II (M443)
893 035 093 C
Made in Germany

on the top of the radio, a sticker with
Volkswagen of America, Inc.
Original WC2
Vendor Code BNO
and the wiring connector label, sticker # 8 631 121 825
Interestingly, although the sticker shows three wiring harnesses
connectors, and there are three on the radio, the middle connector was not
used, and only two are labeled on the sticker.

On the power connector, 8 points:
-       (light) (nothing)       ground
+       sw +A   sw +            (nothing)
between the - and + on the far left is a "Ub" notation

On the signals connector, 10 points:
LR      RR      RC      (nothing)       CL
LF      RF      COM     ENA             DATA
between the LR RR, LF RF points is a "line-out" notation

Incidentally, if anyone wants this head unit, FREE TO A GOOD CAR.  Just pay
shipping (3.5#, add packaging, probably 5#, estimate $10) and I can't do
anything with it (shipping wise) until after Christmas.  Faults:  on-off
switch is flaky (why I pulled it, along w/ the faulty Bose sepakers), and
station buttons 3 & 4 are "soft" (weak springs compared to 1 & 2)

*  Linus Toy                      Insanity is doing the same thing   *
*  Mercer Island, WA              you've always done and expecting   *
*  linust at          different results                  *
*                                      - Roger Milliken              *

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