On Thu, 06 Aug 2015 02:17:25 -0400, micky
wrote:

In alt.home.repair, on Wed, 5 Aug 2015 10:05:16 -0700, "Snuffy \"Hub
Cap\" McKinney" wrote:

"micky" wrote in message ...
In alt.home.repair, on Tue, 4 Aug 2015 16:38:18 -0700, "Snuffy \"Hub
Cap\" McKinney" wrote:

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 battery.

Thanks folks,

Snuffy

Do you have a tachometer? Does the RPM oscillate?

RPM is steady. Oscillating lights happens at slow idle. If I increase idle speed just a little with accelerator, lights are steady.

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?

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

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
reason.

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
bulbs.