Thanks Tom, that is pretty much my opinion also.

"Tom in Missouri" > wrote in message
news
> I'm sure the type of alternator has a lot to do with it being safe or not.
>
> 1963 to 1968 - external mechanical voltage regulator. I can attest you can
> do this without the alternator going belly up.
>
> 1969 to 1980s (depending on vehicle) - not a great idea, but you can
> probably get away with it for the disconnect. I'd shut off before
> reconnecting.
>
> 1980s to 1990s SI alternator - my experience has been it is hard to keep
> it living under normal conditions, I' never try the disconnect unless I
> had a lifetime warranty on it. In fact, all you have to do is take a trip
> and be 100 or more miles from home and it is sure to die. Delco must have
> farmed this one out to Lucas.
>
> The electronic voltage regulator alternators are sensitive to large
> voltage surges or pulses. The worse thing you can do I have found is to
> jump start a car with yours running. As the dead car cranks, voltage is
> pulled way down, with heavy current drain. As soon as the dead car starts,
> the voltage spikes, and then the alternator of the dead car also spikes
> back into the jumper car, so you really get zapped hard.
>
> Odds are the regulator will go south and in a couple of months, your
> battery is dead, not holding a charge, because the alternator has either
> been undercharging it or has been charging with only one or two phases of
> the three phase current an alternator produces.
>
>
>
> "Private" > wrote in message
> news:hFMEg.419914$IK3.206979@pd7tw1no...
>>
>> " > wrote in message
>> ...
>>> If the alternator works, you should be able to start the car,
>>> disconnect one of the battery cables, and the engine will continue to
>>> run. If the engine dies when you pull off the battery cable, then you
>>> know that the alternator is defective. Don't reconnect the battery
>>> cable when the engine is running. Just turn it off and then
>>> re-connect.
>>
>> My training was to never run an alternator car without a battery and not
>> to do this battery disconnect test. This is the first time I have heard
>> the caution not to reconnect a running alternator. Please comment or
>> supply further information.
>>
>> TIA
>>
>
>