Another bad alternator, or a rare case of a Swedish syndrome known as "ground wire burnout"?

Dear Car Talk

Dear Car Talk | Jun 01, 1996

Dear Tom and Ray:

Here's another Saab story for you! My girlfriend has a 1986
900 non-turbo.
It starts fine, idles for a while, then stalls. If you try
to start it, the
battery just acts dead. If you jump start it, it will run
fine until you
remove the jumper cables, then it stalls again. The gauges
and digital
displays jump around just before it stalls, with the
voltage jumping from
5v to 27v. The alternator was replaced a year ago. Please
help me! -- John

RAY: While it could be another bad alternator, it's more
likely to be a
rare Swedish syndrome that Saabs suffer from called "ground
wire burnout."
The ground wire that runs from the body of the alternator
to the engine
block somehow burns itself to a crisp. And without that
ground, the
alternator won't charge, and the car won't run.

TOM: We see this a lot when we're removing Saab
alternators. You go to
remove the ground wire, and it just crumbles. So we usually
replace it with
several ground wires. We gang them together and that seems
to give them
more staying power.

RAY: If a new ground wire doesn't fix it, then ask your
girlfriend if you
can see the original dealer invoice for this car. She may
inadvertently ordered Saab's Poltergeist Package. It didn't
sell very well
in '85, so in '86, they grouped it together with the
sunroof and power

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