[quote=Edd Whatley][quote=Michael Ware]"Ken Weitzel" wrote in message
news:TmWXf.212138$sa3.91988@pd7tw1no...


Mr. Transistor wrote:
I've googled this to death but thought I would give this one last try
here.
I have a 1996 S10 Blazer with Delco radio model #16169165. I can see
that
the previous owner must have installed a different stereo & then when
they
traded it in, replaced the Delco.
I bought the car a month ago and its fine except the radio memory does
not
store any station setting or time. It has three plugs- black, blue, and
white. An orange wire in the black plug supplies 12 volts while the key
is
in the ignition. There are no other voltages present in any plug with
the
key off.

With those 3 plugs in the back of the radio there is still one open
socket
with 7 pins I believe. But there are no other loose cables anywhere to
be
found in the dash. Is the 12 volts necessary to keep the memory supposed
to
be through this plug?

Unless someone has any ideas, my only hope is to apply 12 volts to each
of
those pins to see if the memory keeps without frying the radio.

Someone suggested that the radio might have an internal battery, but
I've[color=blue]
taken the covers off and don't see anything resembling a battery.

If you have any ideas please let me know!

TIA, Steve

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The only thing to add to and complement all of the previous comments is that if you are worried about applying 12VDC to a wire to test......merely do so thru a 470-to-1k 1/2 W carbon resistor as that wioll be adequate for the miniscule memory retention requirements.
I thought that I had online EBSCO Auto Repair info available , but the wiring diagram was not inclusive of the radio. Tomorrow I will check out All Data for
its wiring code colors to the radio.

73's de Edd

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The followinmg addenda added:

Here is what the ALL DATA manual says in reference to the wiring feeding to the radio proper:
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DESCRIPTION AND OPERATION:

Voltage to the Radio is available at all times through the ORN (1140) wire. This
circuit provides voltage for Radio station memory storage. It also provides voltage
for the clock memory.

With the ignition switrch in ACC or RUN, voltage is supplied to the Radio through the
Radio Fuse and the YEL(43) wire. (Each speaker has its own pair of leads.)

The Radio Clock Display is at full intensity with the Ignition Switch in ACC
or RUN; voltage is supplied by the YEL (43) wire.

When the Park or Headlights are turned on, voltage is supplied to the RADIO through
the BRN (9) wire. When the Radio senses this signal, the radio switches voltage for the display from the Yel (43) to the GRY (8) wire. The display brightness is then controlled by the Panel and Interior Lamps Control Switch.

The Radio illumination bulb voltage is supplied by the GRY (8) wire.

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Looking at the radio proper and the power connections it looks like the following associated numbers are on that radio's power connector:

Pin 9.....Ignition power.....hot in ACC or RUN
Pin 10...Battery voltge ....hot at all times
Pin 6.....Display Dim Signal....hot if Light Switch is in Headlights or Park Position
Pin 7 or 8..Internal panel lamp in the Radio (Difference of 7-8 being dependent on radio version)
Pin 5....THE RADIO's GROUND WIRE.....Black with white tracer.

Usually pink is for power antenna but since this unit is not in the Caddie Escalade category
Its probably just as well in still using your recycled coat hanger / antenna......
By the top description , you can see that some internal power routing / switching comes into play in different situations.
That's all the info.....now go tear 'em up tiger!

73's de Edd

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