[V8] battery light on dash came on and a few days later dead

[toml99 at todomundo.com]

Check to make sure it's charging/battery is OK first.  I was testing  
the climate control today in the Black car, and forgot about how you  
can show the voltage on that without getting out the voltmeter.  If  
your car is a 90-91 turn the key to on then hold the outside air temp  
button while pressing the "off button.  That starts the diagnostic  
mode for the climate control(it should read 01).  When you press the  
outside temp button again, it's like the "enter" button and if  
there's a fault code, it get's displayed.  Pressing the warmer button  
goes to 02 then all the way to 21.  Go to channel 11 and hit the  
outside temp button and it will register the cars voltage(do it not  
running/then running).  MIne said 10.8 not running with a fully  
charged battery, and 13.8 running(voltmeter said battery was 12.5 and  
14.1 at the battery.  On this, the heat and fan are full bore, and no  
buttons respond, so I think when I swap the control unit, all should  
be well(no fault codes either).

If you aren't charging, the regulator/brush assembly is cheap and  
while I'm not sure if it's doable without totally removing the  
alternator, it might just solve the problem.  Even the alternator  
that had 225K on it didn't need bearings as they are pretty beefy and  
I think that cooling duct helps for longevity.....Or you need a  
battery/clean your grounds/terminals......Or some huge woodrats are  
living under the back seat and chewing on all your wiring.....Ha...Tom