Kenwood Stereo in 5KCS problem

[Ameer Antar]

50mA is not even close to what is needed for an amplifier. Believe me, no
antenna lead is gonna run an amplifier, well maybe a 1/2W headphone amp!
Unless the rear amps aren't really amps (maybe crossovers), they'd probably
need at least 3-5 amps each. What do you mean by: "but since the unit will
come up with sound playing with the rear amp lead connected to the antenna
lead but the rear speaker connections cut.."? Where is the sound coming
from, the fronts only? Well that makes sense. When you connect the speaker
load to the rear amps, they will cut out as they can't run such a load off
of 50mA. I'm not sure what you were trying to do w/ the resistor, but I
guarantee you  can get the whole system working by connecting the 4 Kenwood
speaker wire ouputs directly to the speakers. If you have separate woofers
and tweeters, it's ok to test on the woofer only first. For permanent
design, all you need is a simple coil and cap for each as a crossover to
separate the high and low frequencies. I wouldn't use chassis ground for
any speakers and I'd avoid it for high power amps, b/c steel is not the
best conductor, especially w/ all kinds of coatings like paint and zinc on
it. Connect everything directly. There is no A.C. power in the car, except
inside the alternator, but even that's converted to DC all inside the
alternator. Another test just to see more possibilities, is to just run a
wire from a 12V supply (battery or there are 12V connections in the
driver's fuse panel) directly to the amps. Just try one. I guarantee this
will keep the amp on, unless there's something up w/ the amp or the wiring.
good luck.

-ameer


At 12:41 PM 7/7/2002, Steve Sherman wrote:
>Thanks Ameer:
>
>I did check (best I could with a cheap digital multimeter) and the
>current out of the antenna lead stabalizes at ~50ma.  Which I though
>should be OK.  You may have something in that this meter is too slow to
>register an inrush current, but since the unit will come up with sound
>playing with the rear amp lead connected to the antenna lead but the
>rear speaker connections cut, I tend to think it is something else.
>
>One other thing I tried, was to connect the + lead of the rear speakers
>to the Kenwood through various resistors (from my junk box collection).
>An odd thing was that even with a 50ohm resistor in series with the rear
>speaker (to rear amp) lead, the problem did not go away, AND the
>resistor got very WARM (this was a 1 watt resistor).
>
>This leads me to think that the excessive current draw is happening from
>the kenwood to the rear amp inputs.  I'm not an EE, but it would seem
>that the BOSE rear amp's inputs are sucking current. Probably need a
>scope or the like to see if the excessive current draw is DC or AC.  All
>the more odd in that only one line per channel is being connected (as
>per archive post).  So the ground/return current path would seem to be
>to chassis ground...  Perhaps the rear amp uses chassis ground for one
>signal line, and thus shorts out the Kenwood amp, as one is not supposed
>to introduce a chassis ground into the speaker wiring.
>
>Any thoughts on this?  Do any listers know what the correct input
>impedance of the factory rear amp is and what a "good" mathching
>transformer/cap would be?
>
>TIA