Simon wrote:
> It is important to note that if this bulb (or the wiring to/from it)
> fails, your alternator will not work!
I remember realizing this years ago and thought it was the dumbest possible
design: if the warning light fails, it CAUSES the charging circuit to fail,
and, of course, it can then no longer give any indication of the failure!
But, it is also true that I have never heard of one burning out. I guess
the bulbs just don't get enough hours on them during the life of a typical
car. Still, it pays to look at it to make sure it comes on briefly each
time the engine is started. Why is it called an *ignition* warning light
anyway - it doesn't have anything to do with the ignition??? I like "idiot
light".
But that is not my question. Does anyone know why an alternator (but not a
generator) will be damaged if operated without a battery in the circuit?
In terms of load, there should not be much difference between having a
fully-charged battery that is accepting little current and having no
battery at all. I presume it is the alternator's diodes that are at risk
but don't understand why. Do they need the 12 V bias?
In my younger, more impoverished days, I occassionally had need to drive my
'63 B (generator) without the batteries in place. Since it was so easy to
push-start, this was convenient way around some problem or another. Ah,
the good old days....
Russ Wilson
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