Amphi not charging

[Al Heath]

After reading the good stuff on the clutch, I'll ask for ideas on this
problem. First history:

Previous owner installed a Postive Ground alternator ... from what I can
tell, it looks like a Motorola AP12X600 with a Delco Remy 9000590
regulator. He said he had trouble with it charging at times, but when I
got it last year, it was charging some ... about 13 volts on a full battery
... low I thought, but at least it wouldn't boil the water out of the
battery. Anyway, recently battery went flat (when he put on the
Alternator, they didn't wire in any amp meter, etc...so it was a "surprise"
.... by the way, the Amphi would run on 9 volts once jump started ... but
when it stayed at 9 volts it deemed more investigaion), so in investigating
over the weekend had these symptoms. Sometimes no charge, other times get
13.2 to 14 volts when rev engine, turn car off, do it again and sometimes
no charge, One "cycle" pegged voltmeter over 16 volts, another time it had
a constant swing 14 to 16 volts.. other times nothing .. nada ... 12.5
(fully charge battery) Take to car to alternator shop and verifies
nothing coming out ... he tests the alternator and when his machine applies
a field voltage, we get current out of the alternator. Assumption, bad
regulator. Get a new regulator (same type which says for either Positive
or Negative ground).... nada .... Check regulator connections, plug,
wire continuity ... all seem good. still nothing ... try old regulator ...
nothing. Check alternator again on machine ... puts out current when
field applied externally. Suggestions??? I'm about ready to wire in a
Generator/regulator from a parts car.
Al

 

[Scott]

Al,

You need to get a single wire alternator. An early 1970s GM alternator can be
converted to a single wire charging system by replacing the internal regualtor.
I bought a regulator from the local car electrical shop for $15 if your the do
it yourself kind. Many of these alternators are being converted for use on old
tractors and old cars with generators. Get an alternator from a salvage yard or
perhaps they can use the one you have. My local guy will rebuild and convert a
core alternator for $45. There is only one wire and it hooks to the battery.

Scott Moses..
Kansas


[Non-text portions of this message have been removed]

 

[amphi_sc]

--- In amphicar-lovers@y..., "Scott" <smosesks@h...> wrote:
> You need to get a single wire alternator. An early 1970s GM
> alternator can be converted to a single wire charging system
> by replacing the internal regualtor.

I thought all those single wire conversions also required
going to Negative ground. This present alternator setup on
Debra's car is still Positive ground ... yes one of those
wierd animals... (I guess that means the diodes are all
flipped from one side to the other, and probably explains the
"AP12" nomenclature for Alternator, Positive 12 volt). Or is
this flipping of the diodes what your guy does for the $45.

Al

 

[jfriese]

If you go to a single wire alternator setup, your charging light won't
work. The charging light circuit feeds the "exciter" lead on the
alternator or generator. I use a Lucas alternator and switched the
car to negative ground. It's a snap to do. With the Lucas setup, you
don't even have to change the terminals at the alternator end of the
wiring. It just plugs right in. And you can get the correct Triumph
Spitfire mounts for it, so it looks "correct" for the engine.

John Friese

--- In amphicar-lovers@y..., "amphi_sc" <aheath@u...> wrote:
> --- In amphicar-lovers@y..., "Scott" <smosesks@h...> wrote:
> > You need to get a single wire alternator. An early 1970s GM
> > alternator can be converted to a single wire charging system
> > by replacing the internal regualtor.
>
> I thought all those single wire conversions also required
> going to Negative ground. This present alternator setup on
> Debra's car is still Positive ground ... yes one of those
> wierd animals... (I guess that means the diodes are all
> flipped from one side to the other, and probably explains the
> "AP12" nomenclature for Alternator, Positive 12 volt). Or is
> this flipping of the diodes what your guy does for the $45.
>
> Al

 

[amphi_sc]

Solved the problem. Sometimes you overlook the obvious. A
quick summary. Positive ground alternator/regulator put on
this car in the late 70's. Regulator gave up regulating...
Numbers on the regulator didn't match anything in the parts
books, but found one that visually looked exactly like it, was
for 12 volt postive or negative ground, had the same 3 wire
plug connector, same physical locations on the attachment
points. So ordered that one for $24 ... It arrives, both the
alternator and regulator bench check. In the car nothing,
back on the bench all ok. Repeat this a few times...
Hum.... then duh, the proverbial light bulb goes off.
Regulators are slightly different in the internal design of
the 2nd stage transistors... open collector vs emittor driven.
... Old regulator sunk the field (that was "grounded" at the
alternator case giving the +12v feed) through the negative
regulator lead whereas new regulator supplies +12 to the field
from the regulator expecting the field to be externally tied
to the "-" someplace. Anyway, testing the new regulator on a
jig, watching the light bulb (emulating the alternator field
load) cycle on and off properly when it dawns where I have the
test light "grounded". Duh... Back to the car ... flip the
field connections and juice. And now can use the alt excitor
terminator and indicator light circuits whereas they didn't
fit in with the old regulator that had been on the car for 20+
years. So I guess you could say it was the assumption that
the new regulator was really a one-one replacement of the old
regulator. The old design only required one switching lead
(just the "-" on the regulator) whereas the design requires
that switched lead, and a switched lead on the field (which
the indicator light can now provide with a little work), or
re-wiring the car more and switching the "+" regulator lead
instead. So I guess I can 1/2 understand why 70's owner did
what they did. As for the low charging the previous owner
experienced, I found an external diode burried in the bilge
wires on the switched negative circuit ... that would give a
.6 volt drop across the diode throwing off the "-" reference
V. Maybe its original intent was to prevent damage to the
regulator if someone inadvertantly hooked the battery up with
a negative ground thus illogically reversing the + and - feeds
to the regulator ... which would probably be quite sensitive
to such misuse. All is well now, got juice and the car still
positive ground so the old fuel guage and old radio and old
alternator don't have to be messed with.

Thanks for the suggestions.
Al