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Ammeter Charging Question - Slight Charge Always #1717519
12/29/14 10:33 PM
12/29/14 10:33 PM
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North Carolina
cjskotni Offline OP
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Guys,

I have noticed I always have a slight charging condition on my 1973 Charger when I am driving it. The ammeter of course pegs charging when you crank the car but then drops down to a slight charge and it stays there. By slight, I mean maybe 2-3 amps. Once the battery is topped off it doesn't matter if you are idling or running 3200RPMs on the highway, this charge is always there.

Wiring is all stock reproduction and gauges were rebuilt by Instrument Specialties. The ammeter seems to be accurate as it is dead center when then car is off. Battery voltage is 14.6V at idle or when revving the motor.

Is this normal? Could this be a battery issue? Or am I worrying over nothing? I am just curious if you guys have noticed this before on your cars.

Thanks!


Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717520
12/30/14 12:33 AM
12/30/14 12:33 AM
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Colorado
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denfireguy Offline
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It is normal.
Craig


2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
Re: Ammeter Charging Question - Slight Charge Always [Re: denfireguy] #1717521
12/30/14 01:13 AM
12/30/14 01:13 AM
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TJP Offline
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I'll politely disagree.
A constant slight charge condition is indicative of a voltage drop somewhere between the Alternator, battery and IGN/ Accessory circuit which includes the Voltage regulator itself, grounds and a myriad of other gremlins.
A kwik Voltmeter test will tell the story. IE: V at battery, V at alternator output, and voltage sense line to the VR. is it enough to worry about??? the difference between the Alt output and battery will answer that question

Re: Ammeter Charging Question - Slight Charge Always [Re: TJP] #1717522
12/30/14 01:26 AM
12/30/14 01:26 AM
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Lincoln Nebraska
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RapidRobert Offline
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Check the ground path(s) also on low (20 volt) scale. alt case to batt neg post/reg case to batt neg post (batt neg post is your reference point). As said break out your meter/check ALL terminals/connections. way less likely would be a batt cell going bad & subbing in another battery would ans that Q quickly. In almost all cases when an electronic reg goes bad it either goes open or full fields


live every 24 hour block of time like it's your last day on earth
Re: Ammeter Charging Question - Slight Charge Always [Re: RapidRobert] #1717523
12/30/14 02:49 AM
12/30/14 02:49 AM
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Valencia, España
NachoRT74 Offline
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1st question I'd do.

DO YOU HAVE SOME EXTRA DEVICE/ACCESORy hooked up to the batt side ? the load reading could be feeding that and not really a charging reading... which when revving up, batt also will demand the power lost when sourcing the acc, then the big charging reading


With a Charger born in Chrysler assembly plant in Valencia, Venezuela
Re: Ammeter Charging Question - Slight Charge Always [Re: denfireguy] #1717524
12/30/14 06:12 AM
12/30/14 06:12 AM
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Bend,OR USA
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Quote:

It is normal.
Craig


For you doubters do you realized that all the current from the Mopar alternators goes through the amp gauges on all Mopars ? That being the case what amount, in amperage, does the Mopar electronic ignitions need to run on, same thing on the engines gauges, how many milli amps do they draw? How many amps does the radio and clock use


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717525
12/30/14 08:19 AM
12/30/14 08:19 AM
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Mopar73340 Offline
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My 73 behaves identical to what you say your Charger does and has been exactly the same way for the last 35 years....

Re: Ammeter Charging Question - Slight Charge Always [Re: Mopar73340] #1717526
12/30/14 09:41 AM
12/30/14 09:41 AM
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North Carolina
cjskotni Offline OP
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Quote:

DO YOU HAVE SOME EXTRA DEVICE/ACCESORy hooked up to the batt side ? the load reading could be feeding that and not really a charging reading... which when revving up, batt also will demand the power lost when sourcing the acc, then the big charging reading




Haha, I know so many people wire things incorrectly. The only non-stock load I have is electric fans and they (their relays) are powered from the alternator stud so when they run, the ammeter shows the proper readings. Everything else is powered from the factory locations.

Quote:

Check the ground path(s) also on low (20 volt) scale. alt case to batt neg post/reg case to batt neg post (batt neg post is your reference point). As said break out your meter/check ALL terminals/connections. way less likely would be a batt cell going bad & subbing in another battery would ans that Q quickly. In almost all cases when an electronic reg goes bad it either goes open or full fields




I am 99.9% sure all my grounds are as good as it gets. I have ground jumpers run from the VR to the firewall tied to the ground strap that goes to the engine block. I would think if grounding were bad, the system would be charging at more than 14.6V.

The battery is a deep-cycle Interstate and is at least 5 years old. It appeared in the engine bay sometime during when my Charger was in body shop hell. I had it tested 2 years ago and it was fine they said (Advance Auto FWIW). Granted this car doesn't get driven more than 1-2x a week but maybe it is time for a new battery.

I'm glad to see I'm not the only one who has seen this. I am electrically proficient (I'd like to think) so I wanted to see if this was normal as I have eliminated the "easy" stuff already.

Re: Ammeter Charging Question - Slight Charge Always [Re: Cab_Burge] #1717527
12/30/14 11:18 AM
12/30/14 11:18 AM
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Supercuda Offline
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Quote:

Quote:

It is normal.
Craig


For you doubters do you realized that all the current from the Mopar alternators goes through the amp gauges on all Mopars ? That being the case what amount, in amperage, does the Mopar electronic ignitions need to run on, same thing on the engines gauges, how many milli amps do they draw? How many amps does the radio and clock use




Wrong. Look at a schematic.

normal operating loads are on the alternator side of the ammeter. You will NEVER see them in the ammeter. If you are seeing a slight charge on the ammeter odds are it's one of two things, someone added a draw to the battery or the ammeter is off.


They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
Re: Ammeter Charging Question - Slight Charge Always [Re: Supercuda] #1717528
12/30/14 02:10 PM
12/30/14 02:10 PM
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Omaha Ne
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TJP Offline
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Quote:

Wrong. Look at a schematic.

normal operating loads are on the alternator side of the ammeter. You will NEVER see them in the ammeter. If you are seeing a slight charge on the ammeter odds are it's one of two things, someone added a draw to the battery or the ammeter is off.



CORRECT!!!



The ammeter indicates current flow to and from the battery. A constant charge indication means the battery is constantly receiving current and potentially being overcharged. This could be due to a draw on the battery side of the circuit or voltage drops between the battery, alternator output and voltage regulator sense line. As designed the battery supplies current when the alternator is not sufficient due to low idle speed, high draw accessories, or when starting.

Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717529
12/30/14 04:39 PM
12/30/14 04:39 PM
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Rio Linda, CA
John_Kunkel Offline
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Read the owner's manual. "The alternator indicator pointer will normally stay centered while driving when the battery is fully charged and no lights or accessories are in use".

Note the reference to lights and accessories.


The INTERNET, the MISinformation superhighway
Re: Ammeter Charging Question - Slight Charge Always [Re: John_Kunkel] #1717530
02/21/15 01:33 PM
02/21/15 01:33 PM
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North Carolina
cjskotni Offline OP
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Well here is an update on this one. I noticed my starter has been getting slower and slower when I try to crank the car...even while cold. When the car was hot, it was a 50/50 chance it would crank fast enough to start!

I also noticed that every so often if the car sat for more than a week, my radio would lose all it's settings.

I got tired of this and checked the battery voltage after a 15 minute drive (and plenty of time to verify via ammeter that the battery was topped off) and battery voltage was only 12.18. I put a mutlimeter in series and verified current draw in only in the 9mA range so no significant parasitic draw really.

I'm guessing my battery was going out! I have the new battery and I will holler back when I get it in and fire up the car!

Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717531
02/21/15 04:31 PM
02/21/15 04:31 PM
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DDodger Offline
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Quote:

Battery voltage is 14.6V at idle or when revving the motor.






Someone mentioned..........make sure you have no loads hooked on the "wrong side" of the ammeter

IE you want no loads hooked to the battery stud on the start relay.

One way to check is with engine off, carefully turn on any suspect loads in the car and watch for an indication on the meter. Stereo amp? etc.

At 14.6, you are "pretty close" optimum is 13.8--14.2 AND CHECK WHEN WARM. The regulator is "temp compensated."

You may or may not have a battery becoming somewhat sulphated. Make sure your voltmeter is accurate. Sometimes, they are not.

Does the battery run "wet" IE tend to puke a tiny bit out the vents?

Last edited by DDodger; 02/21/15 04:32 PM.
Re: Ammeter Charging Question - Slight Charge Always [Re: DDodger] #1717532
02/21/15 05:56 PM
02/21/15 05:56 PM
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North Carolina
cjskotni Offline OP
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Yes the battery had run "wet". I suspect it was sulphated up pretty bad.

Anyways I got the battery in and it fires right up like soooo easily now...even today when it was 25 degrees here. And...guess what...ammeter is DEAD center once the battery is topped off.

My system is wired correctly, period. All loads are taken from the alternator side of the ammeter so it's honest.

I check my charging voltage and it is closer to 14.9V which is higher than I'd like. I traced the voltage drop to the neg battery cable itself which read ~2.5 ohms. Everything else was 0 ohms. I appears my negative cable is coming apart a bit as I wiggled it good and it dropped back down. I guess I am ordering a new negative cable.

The battery was the issue for sure. I didn't realize how fricken slow my starter had gotten.

Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717533
02/21/15 06:00 PM
02/21/15 06:00 PM
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Omaha Ne
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TJP Offline
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thanks for the update,

Re: Ammeter Charging Question - Slight Charge Always [Re: cjskotni] #1717534
02/21/15 08:36 PM
02/21/15 08:36 PM
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DDodger Offline
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Quote:



I check my charging voltage and it is closer to 14.9V which is higher than I'd like. I traced the voltage drop to the neg battery cable itself which read ~2.5 ohms.




That is ONE HELL of a lot of resistance if correct.

But don't try to shoot bad grounds and voltage drop with resistance, do so with voltage tests

Just picture in your mind the path that current takes. "th juice" going to the regulator comes off the battery, through the bulkhead and ammeter, through the ignition switch, harness, etc, back out the bulkhead and feeds to the regulator

There are a couple of places, there, namely the bulkhead connector, the ignition switch and the connector on the switch, that can create drop

Turn the key to "run" but with the engine not running

If you have breaker points ignition, make sure the points are closed, and make the test rapidly

Compare battery voltage to voltage feeding the regulator. On a 69 and earlier regulator check right at the regulator ignition terminal

On 70 and later this is harder. you can check at the blue field on the alternator. If you can get to the "key" side of the coil ballast, check there

What you are looking for here is the difference between battery and that point feeding the regulator. You want less, that is "zero" is perfect. If you come up with more than, say 3/10 of one volt, find out why.

Same with ground only this time, check with engine running fast enough to charge. Put your voltmeter on very low DC volts. Stick one lead to the battery NEG post. Stick the other lead to the regulator mounting, "the case." Here again, zero volts is perfect. Anything more than a 1/10 volt or so, you need to work on grounding.

Back to your neg cable. Here again, best way to check cables "bad" or not is under starting current loads. This is made easy with access to a "load tester." But you can "cheat" by just running the starter, ignition grounded. Check voltage across the cables during cranking.

Re: Ammeter Charging Question - Slight Charge Always [Re: DDodger] #1717535
02/22/15 03:27 AM
02/22/15 03:27 AM
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As was stated the ammeter will show how much current is going into or out of the battery. If there is an extra circuit added to the car it should be on the ign switch side of the ammeter which would not show on the ammeter if the alt is putting out enough current to supply it at idle and if the alt is not putting out enough to supply it at idle then it will draw from the battery at idle which would show a discharge not a charge. Basically if your gauge is showing a charge it is telling you the battery is taking in some current at that time. Even a fully charged battery will draw a few amps to keep it at full charge and most of the stock ammeter gauges will be centered or just slightly on the charge side when all is working good and the battery up to charge. I agree that what you are seeing sounds like a battery problem as I have seen it many times over the years.
Also your 14.9 volt reading you got at what temp was that as it will have a higher target voltage as it gets colder ? I have seen it as high as 15 and even 15.2 volts in 20 degree temps. Course at 70 degrees it should be around 14.2. Ron

Re: Ammeter Charging Question - Slight Charge Always [Re: DDodger] #1717536
02/22/15 03:48 AM
02/22/15 03:48 AM
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Quote:

Quote:



I check my charging voltage and it is closer to 14.9V which is higher than I'd like. I traced the voltage drop to the neg battery cable itself which read ~2.5 ohms.




That is ONE HELL of a lot of resistance if correct.

But don't try to shoot bad grounds and voltage drop with resistance, do so with voltage tests

Just picture in your mind the path that current takes. "th juice" going to the regulator comes off the battery, through the bulkhead and ammeter, through the ignition switch, harness, etc, back out the bulkhead and feeds to the regulator

There are a couple of places, there, namely the bulkhead connector, the ignition switch and the connector on the switch, that can create drop

Turn the key to "run" but with the engine not running

If you have breaker points ignition, make sure the points are closed, and make the test rapidly

Compare battery voltage to voltage feeding the regulator. On a 69 and earlier regulator check right at the regulator ignition terminal

On 70 and later this is harder. you can check at the blue field on the alternator. If you can get to the "key" side of the coil ballast, check there

What you are looking for here is the difference between battery and that point feeding the regulator. You want less, that is "zero" is perfect. If you come up with more than, say 3/10 of one volt, find out why.

Same with ground only this time, check with engine running fast enough to charge. Put your voltmeter on very low DC volts. Stick one lead to the battery NEG post. Stick the other lead to the regulator mounting, "the case." Here again, zero volts is perfect. Anything more than a 1/10 volt or so, you need to work on grounding.

Back to your neg cable. Here again, best way to check cables "bad" or not is under starting current loads. This is made easy with access to a "load tester." But you can "cheat" by just running the starter, ignition grounded. Check voltage across the cables during cranking.



The voltage from the battery leaves it on the negative side just like all batteries and returns through the positive side, the alternator charges from the alternator through the engine wiring harness to the bulkhead connector and then through the under dash wiring harness through the amp gauge and back through the same harness and then goes to the battery to keep it charged. Come on you guys, GET THE BASICS correct before intentionally or unintentionally misleading those that don't know D.C. current flow


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Ammeter Charging Question - Slight Charge Always [Re: Cab_Burge] #1717537
02/22/15 06:02 AM
02/22/15 06:02 AM
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Montana
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DDodger Offline
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Quote:

Quote:

Quote:



I check my charging voltage and it is closer to 14.9V which is higher than I'd like. I traced the voltage drop to the neg battery cable itself which read ~2.5 ohms.




That is ONE HELL of a lot of resistance if correct.

But don't try to shoot bad grounds and voltage drop with resistance, do so with voltage tests

Just picture in your mind the path that current takes. "th juice" going to the regulator comes off the battery, through the bulkhead and ammeter, through the ignition switch, harness, etc, back out the bulkhead and feeds to the regulator

There are a couple of places, there, namely the bulkhead connector, the ignition switch and the connector on the switch, that can create drop

Turn the key to "run" but with the engine not running

If you have breaker points ignition, make sure the points are closed, and make the test rapidly

Compare battery voltage to voltage feeding the regulator. On a 69 and earlier regulator check right at the regulator ignition terminal

On 70 and later this is harder. you can check at the blue field on the alternator. If you can get to the "key" side of the coil ballast, check there

What you are looking for here is the difference between battery and that point feeding the regulator. You want less, that is "zero" is perfect. If you come up with more than, say 3/10 of one volt, find out why.

Same with ground only this time, check with engine running fast enough to charge. Put your voltmeter on very low DC volts. Stick one lead to the battery NEG post. Stick the other lead to the regulator mounting, "the case." Here again, zero volts is perfect. Anything more than a 1/10 volt or so, you need to work on grounding.

Back to your neg cable. Here again, best way to check cables "bad" or not is under starting current loads. This is made easy with access to a "load tester." But you can "cheat" by just running the starter, ignition grounded. Check voltage across the cables during cranking.



The voltage from the battery leaves it on the negative side just like all batteries and returns through the positive side, the alternator charges from the alternator through the engine wiring harness to the bulkhead connector and then through the under dash wiring harness through the amp gauge and back through the same harness and then goes to the battery to keep it charged. Come on you guys, GET THE BASICS correct before intentionally or unintentionally misleading those that don't know D.C. current flow




you can take your two cents and you can go stick it somewhere

i simply IN SIMPLE TERMS described the CURRENT PATH. the PATH that the current takes, JUST ENOUGH of the description to ILLUSTRATE THE POINT which is the "direction" in which most people probably "think."

It matters not, oh engineering xpert, "which way" the current flows, and by the way, it wasn't all that long ago (in the 20's) when people believed there was "current" going from plus to minus.

I WAS ATTEMPTING TO ILLUSTRATE IN NOT TOO TECHNICAL TERMS how voltage drop occurs. The probability is, if someone is wondering what the drop is "doing" that they will be measuring and troubleshooting "from the positive end" of the system rather than the "ground" end. That is all I was trying to illustrate. THE WAY THAT VOLTAGE DROP HAPPENS

NOW I NOTICE that YOU the ENGINEERING XPERT "did not" attempt to illustrate anything helpful, anything factual, anything concrete. I notice that you made NO helpful contribution AT ALL.

You did not suggest, for example, that the voltage regulator must be held that is "grounded" very very close to the battery NEG and therefore to remove, clean, and retighten the VR mounting bolts. I notice you DID NOT suggest, as an example, to examine and to check the VR connector(s) and to be sure they are clean and tight. I further notice, as yet a further example, that you did not suggest how to functionally go through the checks for bulkhead, ignition switch, and it's related connector. I NOTICE that you did not SUGGEST ANY of this.

Don't you feel "helpful?"

"I'd bet money" I've been involved with things electrical and electronic longer than you. Statistically, it's "bettable."

Last edited by DDodger; 02/22/15 06:06 AM.
Re: Ammeter Charging Question - Slight Charge Always [Re: DDodger] #1717538
02/22/15 11:03 AM
02/22/15 11:03 AM
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ahy Offline
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Just a comment to tie two things together... charging voltage and weak battery. Voltages over 14.5 after running are too high and will cook the battery with time. An OE MOPAR regulator will back off voltage as the engine compartment warms as low as 13.2 - 13.5 volts to protect the battery. The constant charge you were seeing was probably overcharge of the battery. Basically "boiling" it.

Sounds like the battery cable needs attention and possibly other areas. The voltage regulator needs a positive ground. Any paint or crud behind it can cause an overcharge situation. Scraping some paint off the mounting tab and adding a ground wire to the engine block is a good diagnostic. Also the regulator itself may be bad.

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