David, etal:
<<Keep in mind, the Lucas Volt Meter is slow to respond to voltage changes.
I
have one hooked up and it takes several seconds before the needle moves at
all, and about 1 minute before it is registering the correct voltage. If
you just touch it to the + terminal and expect it to register immediately,
it won't. They could be working fine, and you are not just waiting long
enough for the gage to show voltage.>>
Although I am NOT familiar with the number(s) of Lucas units of the ilk of
what I surmise we are speaking; YOUR experience indicates a secondary
resistor within the gauge. "Most" Stewart-Warner (etc) unit read
immediately.
<<Amp meters are dangerous>>
NOT so.
<< and are no longer used on modern cars.>>
True. The circuitry used in current vehicles called "cars" practically
prohibits because of the computer chip, etc..
<< To work properly FULL generator/alternator current and all vehicle
system load must
pass through a single wire through a hole in the metal firewall, to the
gage, and back out the metal firewall UNFUSED! >>
NOT necessarily so.
Ergo; External Shunt style and Internal Shunt style (of which you speak,
David.)
And I HAVE seen one or two designed systems in the External Shunt style
FUSED.
On the un-reliable side because of extra connections, but fused.
<< One short, and you have one crisp car.>>
Your "scenario" = possible.
For your own education (all of you), take a trip down to your local Fire
Station. Request to speak with the Officer in charge of either Maintenance
or Apparatus Specifications.
Ask about both Voltage System Indicator(s) AND Amphere Indicator(s) Systems.
Return to me thereafter.
Ed
PS: Only spen a couple decades designing same for Rescue/Small Fire
Fighting Trucks and ambulances<G>!
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