The likelihood of the alternator catching fire is pretty remote.  With
the B lead open, there is no current in the output windings, so no
heat.  The field windings could be in a runaway condition where more
voltage produces more current which produces more voltage.  The field
winindings would get hot - till they fail, then no more heat.  The
downside of this type of regulator failure is destruction of the
alternator. With the external regulator and an OVP module, you can pop
a circuit breaker to insure interruption the field current.

Bob W.



On Fri, 9 Sep 2005 07:34:45 -0500
"Mark R Steitle" <mark.steitle@austin.utexas.edu> wrote:

> I first explored this issue after Bob Knuckols expressed a dislike of
> internally regulated alternators...because they can fail in such a way
> that you cannot shut them down.  Yes, you can interrupt the "B" lead,
> but this will not shut down the alternator.  I imagine it could get hot
> enough to self-destruct and possibly catch fire.  
>

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