This just started.... or at least I just noticed it. With the
headlights on dim and engine warmed up and idling, the brightness cycles
from normal to slightly dim. Cycle time is around a second. When I rev
the engine slightly, they return to normal steady brightness.
When running with or without lights, the ammeter is just right of
center, slightly charging, in the normal position.
I don't suspect a connection -- within the last 2 months, I removed and
cleaned all the battery connections, including regulator and other parts
when I was fixing a grounding issue.
Battery cranks start just fine. No other indications of failing
anyway) 12 pole 3 phase devive, and is geares about 2:1 from the
crank, so at 500RPM idle would be turning about 1000RPM, making about
60Hz power (if my math is anywhere close to correct) so any cycling
would be in the 1/60th second range -a very high frequency flicker,
not a surge with a 1 second period.
On Tue, 04 Aug 2015 19:11:55 -0500, "Dean Hoffman"
a month or so, and the unsteady lights at idle will go away when the
alternator is replaced.
How many miles are on this beasty, and how old?? Is it the old
I had the same problem on my '89 - replaced the regulator - no joy.
Replaced the alternator - problem fixed.. I managed to pick up a good
recently replaced rebuild at the wreckers for $30 (about 20 years ago)
In alt.home.repair, on Wed, 5 Aug 2015 10:05:16 -0700, "Snuffy \"Hub
Even at steady RPM, the reguator relay goes in and out, but I really
don't know at what rates. IIRC a generator needs a regulator with 3
relays, and an alternator needs 2 relays.
One of the two limits how much current goes to the field winding, but
is that only for generators?
Do you have a wife with another car. I always wanted a wife with a
pickup truck, but I coudlnt' find one. What's the worst that can
happen, youll break down onthe way to work adn she'll have to pick you
up and take you to work and the car will sit there until you can get a
new alternator. Can you get one right away and replace it wherever the
car dies, or would you have to be towed?
What's the voltage of the alternator, while the lights oscillate.
While they say 13.6 is what it should put out, and maybe lightbulbs are
designed for that voltage, really anything over 12 6 should charge the
battery a little. Or say over 12.7. You said your ammeter shows
slight charging. If the alternator will to completely fail, you could
drive more than a day I'll bet if you have a fully charged battery.
Old cars start easily and cars don't need too much current to run.
I once drove from NYC to Chicago to Indianposlis to the Pa. Turnpike
near Pittsburgh. When I left NY, maybe by the time I got to Ohio or
earlier, the headlights were dim, but as I usually do, I igonred the
problem. The rest of the car ran well and most of my driving was in the
day time.**. I drove to Chicago and around there for 2 or 3 days, Indy
for a couple day, and just as I got to the big gas station near the
entirance to the Pa. Turnpike (after a trip of 1400+ miles.) the car
stalled and woudn't start. I opened the hood and the fan belt that
drove the alternatas literally hanging on by a thread. Of course a
fanbelt thread is thicker than sewing thread, maybe half a millimeter.
But the belt was no longer tight enugh to drive the alternator and I had
been running on the battery for at least a couple hundred miles, and
that was in the dark and again I'd noticed that the headlights weren't
very bright. But the road had been well marked and I coudl follow the
car in front of me, etc. . IIRC, I had a fan belt in my trunk, that I
had taken from a junk yard car like mine, and I put that on, and after I
got some food I got the gas station guy to come the 100 feet to my car
with his portable jumping thing, and I'm not even sure he charged me,
but he started me and I started driving east and charging the battery.
And that was the end of the story.
Now I was in my 20's and people our age don't live like this, but otoh,
if I were just drivign around town, and I had someone to come and get
me, even the number of a taxi-company. I'd still do it that way.
Because you don't yet know that the alternator is bad or that you'll
*have* to replace it before the car fails permanently for some other
In the old days the oil light would flicker on and off at idle and that
was normal, even though it's a lot more imporant that a few little light
In alt.home.repair, on Thu, 06 Aug 2015 16:26:00 +1000, John G
You're definitely wrong about that. Atlternators made their first
showing in large numbers maybe in 1965 or about then and all of them had
relay-based regulators, with two of them, for several years. Then some
had relay-less regulators within the alternators, but they made cars
with both styles for a while.
I guess I was forgetting sold-state regulators and assuming no matter
what year his car is, he had relays. My mistake. (I don't know if
they ever made external soldi-state regulators.)
In alt.home.repair, on Thu, 06 Aug 2015 16:26:00 +1000, John G
Maybe you were thinking about the diodes in the alternator**. If they
had had to depend on diode tubes, whether glass or metal, instead of
semi-conductor diodes, I don't think alternators would have been
**For the youngun's here, if there are any, generatos had a commutator
and generated DC current. Alternators had two rings for the two
brushes, no commutator, and generated alternating current, hence the
name, and used diodes to turn it into DC.
Alternators became standard in the early sixties, and Ford and GM were
still using electromechanical regulators on their alternator systems
up to 1978-79. Mazda still used some as late as at least 1981 and
Toyota untill 1986. Chrysler used then till about 1979.
There are no relays in toda's regulators. They are all electronic.
Some regulate the feild with a PWM, others just switch resistance like
the old relat type.
Generators needed to control maximum current as well as maximum
voltage, AND disconnect from the battery when not charging(cutout) so
the generator didn't "motor" and draw all the power out of the battery
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