Hi group:

My friend's 1997 Olds Aurora has an interesting problem.  The DC
voltage coming off the alternator is to high....up to 17 volts.

He took the car to the local GM dealer and after their diagnostic
service, they said the alternator was defective.

He then took the car to an alternator shop and when the alternator was
pulled from the car and tested on the bench, it's voltage was OK.  The
alternator was rebuilt, anyway, and after it was installed back into
the car, the high voltage continued.

What's left?

Now the serviceman at the alternator shop is thinking that the Battery
Thermistor may be the culprit?  One has been ordered from the GM dealer
and when it arrives in a day or so, we may have the answer.

I looked thru the GM service manual and it doesn't seem to address the
problem except in a general way thereby suggesting that the alternator
is bad.

Also absent from the manual is any information about how you test the
Battery Thermistor.

It's my understanding that the Battery Thermistor is a solid state
variable resistor.  As such, if it were "open," then the car wouldn't
start; if it were "shorted," it wouldn't perform its function and
reduce the alternator voltage if the battery, located under the
Aurora's back seat, were to heat up.

So if it's not open or shorted, what other condition could it be in so
as to not being able to perform it function in the alternator-battery
circuit?

Have any readers experienced this problem with their Aurora?

I look forward to your comments.

Regards,
Al Gershen
Grants Pass, OR
gassyal@hotmail.com