Message text written by Randall Young
>
>If you really want to isolate high charging current from the rest of the
>wiring, one way would be to use a high current diode from the alternator
>output to the starter solenoid. It won't conduct until the voltage across
>it rises to about 0.7 volts, which isn't enough to harm the wiring, but
>will bypass any excess.
>
>Or, I can probably brew up a circuit using the old regulator, an external
>relay, and a "battery isolator" to bypass the original charging circuit
>when the current gets too high, but it hardly seems worth the effort.<
Randall, my idea, poorly expressed, was to brew up the "batttery isolator"
you
describe. I want to protect the original wiring from the full charging
current, but
retain the ammeter as is. Even a shund across the back is OK only if the
brown
and brown-white wires are big enough, which I thought they were not.
I had not thought that the original wiring was sufficient for 60 or 90
amps. That
brown-green wire going to the regulator looks like 12 gauge at the best.
Is it really sufficient
to carry that amperage?
A high current diode with a 0.7 voltage drop seems just the ticket! When
the battery is low,
it will pass current and bypass the main wiring harness and go directly to
the battery. When the
battery is charged up fully, it will not draw that kind of current to cause
a significant voltage drop.
One question though, what kind of current do I have to draw through the
original wiring to create
more than 0.7 volts drop? I'd have expected more than 30 amps..... So,
maybe the simple diode
is not sufficient to adequately protect the original wiring.
Do you have any more thoughts about "brewing" up a circuit with an old
regulator?
-Tony
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