Usually not True. Handheld meters current circuit usually uses
a single shunt. That is the cheap ones. It won't matter what
range he uses.
The more expensive, better made meters usually use two, and in
that case a different range will place a different value shunt
in the circuit.
I can't help thinking that he hooked it up wrong, because there
is nothing about such a small resistance that should stop the
charger's circuitry from sensing a battery in need of charge in
place.
That is more likely. If it even has one. Again, the cheaper
meters do not, and the better ones do .
Current metering that incorporates a fuse does so IN series with
the shunt, and it is the shunt, and other meter circuitry,
including the probe leads that the fuse 'protects' from
over-current conditions.
I can still remember a co-student back in '76, placing a meter
on the AC line with it set to current. It fried the Heathkit
totally. It was only $36, but back then that was a lot for a
student. Now, the fuse, which is nearly always incorporated in
all but the cheapest meters, would open, protecting the meter
guts.
Still, either shunt resistor should still be low enough in value
to have no effect on the charger's sense circuitry. I am
leaning toward there being a blown fuse. On the lowest setting,
and ammeter can even pick up "current" from local induction, so
even with the fuse blown, he *may* see some numbers flickering
across the display.
