What exactly is the Amp gauge telling me?

[showbizkid]

Believe it or not, I've never owned a car with an ammeter before [:0] and so I watch with interest as the needle does its little dance during driving.

Generally, at idle or cruising, the needle is in the middle of the scale or a little on the "C" side. But when I use the turn signal, or step on the brake, the needle deflects to the "D" side a little bit. And if I'm driving at night, with the head and taillights on, the needle dips halfway toward "D" when the car is idling, and dash lamps dim noticeably.

I've had the alternator rebuilt by the best shop in North County, and it certainly seems to be working well.

So, is this behavior normal for a '63 V8 Lark with A/T? Or do I need to replace the voltage regulator? It's the only electrical part I haven't replaced yet It's one of the solid-state Chrysler units, but still...

Any enlightenment you can bestow on me is appreciated.


[img=left]http://members.cox.net/clarknovak/lark.gif[/img=left]

Clark in San Diego
'63 F2/Lark Standard

http://studeblogger.blogspot.com

https://www.studebakersandiego.com

[Tom Bredehoft]

If you had a generator, I'd feel confident telling you this, but with an alternator I'm not sure

With everything off the ammeter should be at neutral, the middle of the scale. If you put your head lights on then, it moves toward D or discharge, because the electricity is coming from the battery and not being replaced by the alternator.

With the engine running, at idle, with no load on the power supply, it should be just to the C or charge side of the middle. As the engine picks up rpms, the needle moves more toward the C until the battery is fully charged, then it should go back almost to the middle. As you turn on electric load, the needle moves more toward discharge, as the engine speed increases (as the alternator speed increases) the needle moves toward the C. So long as the needle is toward the C side when running, there's nothing to worry about. If you're driving home at night with a full load, AC Stereo, lights, and it suddenly goes to D, kill the stereo and the AC and hope you can get home on the battery. Because your alternator has quit. It usually doesn't happen, but you car is now 47 years old and anything can happen.



[img=left]http://www.alink.com/personal/tbredehoft/Avatar1.jpg[/img=left]
Tom Bredehoft
'53 Commander Coupe (since 1959)
'55 President (6H Y6) State Sedan
....On the road, again....
'05 Legacy Ltd Wagon
All Indiana built cars

[edpjr]

I'm not sure what my Studebaker amp gauges are telling me either! The one in my '63 Avanti hovers around the neutral point night or day. The car has a new regulator, a new alt belt, and a $140 high capacity battery. The alt checks out ok too.

Conversely, the amp gauge in my '66 Commander always reads slightly to 1/2 way charging. That car has a battery less than a year old and always cranks fine.

edp/NC
'63 Avanti
'66 Commander

[long1776]

We have to take into consideration that the original alternator was, IIRC, 35 or 42 amps which was marginal even as new. Todays alternators put out 110 or even more amps, but of course the load has increased dramatically too. Another point is that while output has doubled or tripled, the physical size is less today, making the alternator run much hotter.

[Rerun]

quote:What exactly is the Amp gauge telling me?

Simply stated, your ammeter is telling you whether your battery is charging or discharging.

At low RPM, with electrical loads like headlights and accessories, the alternator cannot produce enough power to carry the load. The battery will then be supplying part of the power, and you can see how much amperage it is discharging by looking at the ammeter. When you rev the engine, the alternator will produce enough power for the load. If the battery has been discharged, the alternator will also charge it, as determined by the voltage regulator.

Starting the car will discharge the battery. After starting, you should see the needle remain to the C side for a while until the battery is up to full voltage. When the battery is fully charged, the needle should remain centered in the ammeter, since the alternator is supplying sufficient power, and the battery is fully charged.

I hope that answers your question.

Jim Bradley
Lewistown PA
'78 Avanti II

[Gunslinger]

All an ammeter tells you is the rate of charge or discharge. If it stays centered, the alternator rate of charge and battery rate of discharge are equal and all is nominal. What an ammeter doesn't tell you if the system is charging volts...it only tells you amps. You can charge amps but no volts and end up in trouble. That's why ammeters are rarely seen in cars since the 1970's...most have voltmeters now as it's a more useful gauge to have.




Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, cocky and in general a malcontent.

[jackb]

your description describes a good running electrical system as long as your needle goes to the "C" side at road speeds (>30 mph), and eventually settles midway.

[JimK]

quote:Originally posted by Tom B
but you car is now 47 years old and anything can happen.

This can take far fewer than 47 years to occur! BTDT

I wondered why the lights seemed brighter for a while just before the alt gave up (this was on a VW, your alt may behave differently).

Jim K.
63 Hawk

[cbonner757]

My ammeter in my 51 Champion (6 volt generator) deflects according to load as you describe, but sometimes the needle bounces as well. What would that indicate?

Clarence

[Gunslinger]

If the needle bounces or wiggles back and forth, it's the voltage regulator. The points in the regulator cause that and it isn't unusual. Some are just worse than others at doing it.




Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, cocky and in general a malcontent.

[showbizkid]

Thanks for all the great illumination, guys! Sounds like my system is working the way it was engineered to Moving on to the next fixit, now...


[img=left]http://members.cox.net/clarknovak/lark.gif[/img=left]

Clark in San Diego
'63 F2/Lark Standard

http://studeblogger.blogspot.com

https://www.studebakersandiego.com

[cbonner757]

Thanks, Gunslinger! It seems to charge well, and the lights are brighter than I'd expect from a six volt. Sometimes leaving something alone is
the best solution.

Thanks,
Clarence

[dallastx75208]

If I have read everything correctly mine is not working. It was but now it is showing just below the center and if I turn anything on it goes down further, depending on what I turn on.
What should I check, volt regulator or generator?
And how do I check them? I do not understand volt regulators or generators.

quote:Originally posted by Rerun

quote:What exactly is the Amp gauge telling me?

Simply stated, your ammeter is telling you whether your battery is charging or discharging.

At low RPM, with electrical loads like headlights and accessories, the alternator cannot produce enough power to carry the load. The battery will then be supplying part of the power, and you can see how much amperage it is discharging by looking at the ammeter. When you rev the engine, the alternator will produce enough power for the load. If the battery has been discharged, the alternator will also charge it, as determined by the voltage regulator.

Starting the car will discharge the battery. After starting, you should see the needle remain to the C side for a while until the battery is up to full voltage. When the battery is fully charged, the needle should remain centered in the ammeter, since the alternator is supplying sufficient power, and the battery is fully charged.

I hope that answers your question.

Jim Bradley
Lewistown PA
'78 Avanti II

[Tom Bredehoft]

Jon, you'll have to take it to an automotive electric shop. If you take the generator and the regulator (round, cylindrical thing with a belt driving one end, and little black box screwed to the inner fender and wired to the generator) in to the shop, they can make sure everything is working well and compatible. They want both pieces.

The generator is a very simple machine, the inside goes around and makes electricity. However, there are contacts (brushes) that wear out and no longer make contact, these are easily replaced and you will be back in business and confident that all is well.

[img=left]http://www.alink.com/personal/tbredehoft/Avatar1.jpg[/img=left]
Tom Bredehoft
'53 Commander Coupe (since 1959)
'55 President (6H Y6) State Sedan
....On the road, again....
'05 Legacy Ltd Wagon
All Indiana built cars

[curt]

[quote]Originally posted by Gunslinger

If the needle bounces or wiggles back and forth, it's the voltage regulator. The points in the regulator cause that and it isn't unusual. Some are just worse than others at doing it.

I had an amp needle bouncing (flickering) in the pos side of the amp meter when driving. The shop said doth regulator and alt were working fine. I left the car at the shop: They said the line from the regulator to the ing-switch(?) was the problem. He just ran the line from the regulator to the coil. the ofenfing line was missing when I picked up the car. Anyone have any comments? They are always a help. Car works fine and amp meter reads normal with that fix.