I learned that turning the DC current to the alternator field off did
not stop it from generating juice. I'm wondering, if I then ground that
energizing wire to the field windings if that will do the job.  Karibian

Probably not completely. The rotor is made of "soft iron" but it still
maintains some
residual magnetism. ("soft iron" is ferrous material that is easily
magnetized or demagnetized.
It is used in electromagnets, transformers, and other magnetic devices that
must change
the amount of magnetic flux frequently.)

That residual magnetism is what allows a alternator to bootstrap
from a dead system. That feature is of no value in modern vehicles, because
you have
to have enough battery to start the engine in the first place. If the
battery has enough capacity
to run the electric starter, it has enough to excite the field of the
alternator.

If you really want to make sure the alternator is not contributing to an
electrical problem,
you will have to install a relay to open the output circuit. This would
prevent an internal alternator
failure (e.g. shorted diode) from discharging the battery. Of course, it
would introduce its own
problems.

You pays your money and takes your choice.

Cheers,

Doc Custer
Retired Software Engineer and sometime Audiologist


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