Charged Down


I have upgraded my old points to an
electronic distributor with the ECU. I
have also removed my generator and
converted to a 60-amp double field
alternator and an electronic (transistorized)
voltage regulator. But I am unclear
how I am supposed to wire the extra
field output from the alternator. I left
it disconnected and it seemed to be
charging OK, but the alternator seemed
to get really hot. The next day my battery
was dead. I was afraid that I had
fried something else, but when i charged
the battery back up, it fired right up. I
disconnected the battery until I can find
an answer, so as not to ruin anything.
I have read that it should be grounded
to the alternator but other stuff I have
read says that it needs to be connected
to the voltage regulator. I have looked
for any sort of wire diagram, but haven’t
had any luck. Any help would greatly

It wasn’t charging OK. In fact, it wasn’t
charging at all, and any heat you felt
migrated from the cylinder head, cooling
system air, etc. All 1960–’80s Chrysler
alternators—all—have two field connections.
On the 1960–’69 version, the
second connection was “automatically”
grounded to the case. On 1970-up, the
second field terminal became a terminal
lug, no longer grounded—these are
called “isolated field” alternators. This is
because the electronics of the day were
more reliable if connected to the low
(ground/return) side, which allowed the
use of less troublesome N-P-N semiconductors,
if that matters to you.

Anyway, you didn’t say which version
regulator you have, so I’ll describe both
• If you have installed a OEM-design
1970s “flatpack” regulator, the second
field terminal must be connected to
ignition-on +12V (blue), see diagram,
• If you have installed one of those Chinese
“conversion” electronic regulators,
designed to be plug-’n’-play for
1961–’69, and mimic the OEM appearance
for those years, the second field
terminal must be grounded.
As you have it connected now, there
can be no field current, hence no excitation,
therefore no charging at all—as you
have proven! I guess you could say you’re
in left field!

This diagram shows how to use a ’70s style isolated field alternator and regulator in an earlier
Mopar. Only one wire need be added (blue), as shown, from the second alternator field terminal,
spliced to the existing blue wire that runs from the ballast to the regulator. You’ll need,
obviously, the connector and regulator.

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