It's way too late and I'm way too tired but I'm going for it;
There does have to be something more to what Steve described, not only
because of what Gary pointed out but also because a light bulb in series
with the charge output of the alternator would seriously limit the
charging capability of the alternator. Could the light bulb possibly
sustain 10-30 amps or more of current? Not likely. So there would have
to be a shunt (or relay like Gary suggested) around the light bulb for
this to work, and there may be. However, is it possible we are talking
about a GM three wire alternator here? This also have internal voltage
regulators. There is a field wire that can be connected directly to the
BATT lug and a "R" wire that is used to drive an idiot light. When a
three wire is used to drive an idiot light the light is placed between
the switched hot and the "R" terminal kind of like what Steve described.
Here is one of many links to describe this;
http://www.oldengine.org/unfaq/10si.htm
If, however, we are indeed talking about a true 1-wire (no field and "R"
terminal) then I stand with my initial observations.
Frank
B9471116 (will be equipped with a 3-wire GM Alternator)
|