87 4000cs Alternator failure? (Nolan Gilliam) rukshawmaster at msn.com

[Grant Lenahan]

Let me comment one point at a time, not sure if any answers you "big 
picture questions"  but useful (i hope) nonetheless:

Grant
On Jan 14, 2007, at 7:09 PM, Nolan Gilliam wrote:

> So it got really cold this week up in the Seattle area. Last night I 
> noticed
> my stereo cutting out. The voltage meter in the center console was
> displaying volts around 8 which is pretty low. Battery warning light 
> came on
> as well and my tachometer was bouncing around like crazy.
Normal - below ~10V the 9v regulated system cannot operate, so displays 
and gauges are a craps-shoot.

> This was all while
> I was driving too. So this morning I start the car. She turns over
> hesitantly and the tach is bouncing around and the idle has a mind of 
> its
> own as well...

> I keep the revs around 3k for for a good few minutes to try
> and warm the car up.

If you have nto choice - bad idea from wear perspective you know. very 
bad.  Worse than most people imagine.

> I let her back down to an idle and she stalls out.

Suggesting the cold-weather richening circuitry is nto working.  aka 
5th injector (this is an old car, right?)

> Tried to turn her over and the battery is dead. So i get a new 
> battery, pop
> it in and she starts up fine. No electrical failures at all. Drive it 
> to my
> parents house, watch Seattle loose to Chicago  Come back home and then 
> leave
> for work. While I'm driving i notice the volts output is really low 
> again
> and the stereo starts to cut in and out. So obviously its not a bad
> battery...Does this sound like an alternator issue? Faulty ground?

Could be:
1.) alternator
2.) voltage regulator
3.) ground

All of whcih can be tested. So why are you asking us, typically 1000 
miles away? :-)

Grant
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