poll about ammeter reading

[DeltaV]

Lucas Electric ammeter or a different brand?

 

[dadsbee]

LOL, sad part with this forum is there is always at least one member that can't pull their pinky ring out of their *** and play nice.

 

[Ron H]

I usually have to wonder why some toss out a red X without any explanation. Here's an article taken from a couple year old thread on this subject from our forum:
http://madelectrical.com/electricaltech/amp-gauges.shtml

Of course there's the question of wiring deterioration, wiring design, etc. since the auto MFG's never considered making vehicles to last a half century or more. My BH got partially melted from the amp gauge feed and could be related to my installing a 1st gen Mopar electronic ignition system requiring a higher output alternator. Could be the connector was less than stellar. Most of my add on's have come later since cutting off the amp gauge feed and installing a new engine harness.

 

[72RoadrunnerGTX]

I usually have to wonder why some toss out a red X without any explanation. Here's an article taken from a couple year old thread on this subject from our forum:
http://madelectrical.com/electricaltech/amp-gauges.shtml

Of course there's the question of wiring deterioration, wiring design, etc. since the auto MFG's never considered making vehicles to last a half century or more. My BH got partially melted from the amp gauge feed and could be related to my installing a 1st gen Mopar electronic ignition system requiring a higher output alternator. Could be the connector was less than stellar. Most of my add on's have come later since cutting off the amp gauge feed and installing a new engine harness.

Explanation? “From what I've read stock ammeters were a hazardous setup.” I strongly disagree with that statement, nothing personal. As for the often-cited Mad Electrical article used to backup that statement? It has been a source of contention for years here. I’ve addressed most all of the misinterpretations many seem to take away from reading that article previously multiple times.

Some examples of past discussions about the Mad Electrical article.

 

[440+6]

Funny how someone could think a mellted bulk head connector is caused by an ammeter.

 

[Ron H]

Funny how someone could think a mellted bulk head connector is caused by an ammeter.

Did I say that? Read my post again pal.

 

[383man]

LOL... some you are overthinking this.

Car in good conditions, everything working as must be and we get 0 ( or centered needle ) reading on ammeter while driving around. Don' think something is damaged or not working propperly. You are driving and looking the ammeter ammeter is centered. what do you think ? alt is or is not working ?

Remote/shunt ammeter will read exactly the same than a full load ammeter. They just work with diff signal levels.

No a shunt type ammeter will not read the same as a full series ammeter. The shunt carries 90% of the load and I have worked with many and most of the time with a normal charged battery and the car charging most shunt type ammeters wont move enough to even see it. Heck I have turned the headlites on with the car not running on shunt type and the amp gauge did not even move. They wont show a discharge anywhere near as easy as a normal series ammeter will. Turn the headlites on with a series ammeter and the eng off and you will see the amp gauge move a lot. The shunt type are not as accurate but they went to them so customers would not complain so much of the amp gauge showing discharge at night with the lites and heater on at an idle and then swinging back to charge when hitting the gas. The reason they went to a shunt type was so it wont move as much as a normal full series ammeter and customers wont complain the amp gauge moves to much. Ron

 

[383man]

Also because the shunt and series type ammeters read different you should say which style the car has. A normal car with the amp gauge centered while driving is working normal and charging but with a series type ammeter it wont take much to make the amp gauge move. Like come to a stop and put the turn signal on and see the amp gauge swing some everytime the turn signal comes on. You wont see that with a shunt type ammeter unless it has a low battery and is not charging. With a shunt type in normal driving you rarely see it move but the series type like most 60 's Mopars had you will see the amp gauge move in your normal driving. Course while driving at a steady 50 mph and nothing changing in the car with the series type amp gauge then yes it will stay in the center with a charged battery and the car charging. But normally when you hit the brake and come to a stop at an idle the needle will usually move a little and more if anything in the car is turned on adding a load. But you wont see that on a shunt type gauge much if any with everything working normal. Course you have to remember I am talking about the cars we love of the 60's and 70's with 30 to 45 amp alt's. Ron

 

[Daves69]

I've never seen a functioning ammeter so I really don't know...

Lol, here ya' go. My '69 is pretty much centered when off. North of center running........

Electronic ignition conversion and regulator.

 

[Nacho-RT74]

@383man

I meant a shunted ammeter will get same result on a charge/discharge reading! Or 0 reading. Diagnosis based on its reading is the same. Then we can discuss or be agreed or not on the load actually handles or accuracy, but readings will mean the same on both kind of ammeters, shunted &/or full load

Shunted ammeters were began to use not because "customers claims" but because get a "safer" way to read the load status installed on cluster. It is less sensitive to the small flickering but not necesarilly less accurate on an average reading. Shunted ammeters are indeed the standard system on the testing procedure tools for loads.

Plus, most of the shunted ammeters are now rated to read +/- 60 amps, where the +/- 3 or 5 amperes reading will mean less needle move, so is harder to get a noticeable move with the same load demand

Let's also think cars began to get more electrical devices as standard option so alternators output began to be higher. Since 75/76 most of the 30-45 amps alts if not all were gone, and 50-65 amps began to be the standard. Not by casuality same moment the shunted ammeters floated on. With higher outputs alts, also the flickering on ammeters is reduced. Several small upgrades here and there makes a bigger and better result.

With my "78 amps" alt ( and I say "78 amps" because it got 100 amps decal on it but I seriouslly doubt it ) using the full load amm on my 74 I press brakes and ammeter doesn't even flicks at day light. On nights just small hard to notice flick ( but I have halogens headlights ). So is not necessarily a deal about being shunted or not, but the load feed/recovery capacity of the alt along with correct paths and a good regulator with good wiring too to get a fast response to the added load on that moment.

I changed the big pulley it came of course for the smaller pulley

 

[Nacho-RT74]

@Ron H

ammeters are same hazzarous than the car itself:
-a car is a time bomb carrying a tank full of gas which can explode anytime with all the electric stuff.
-a car without brakes is able to kill ppl ( inside and outside )
-a car which blows a tire could make you loose control and kill ppl
-a car with bad timing can get backfiring through the carb and get on fire everything. In fact is easier that could happen and more common than get your car on fire due the ammeter failure


so, same as get the correct timming, replace brake pads, check brake fluid lines for leaks and check your tires, the electrical stuff, including ammeter has to be checked, mantenienced and understood how it works to prevent failures



Madelectrical stuff about ammeters is mostly full of BS. They are attacking incorrectly the real problem, aside they say with their mod the main splice is being moved to the engine bay, which is false. There is no way to change the main splice from inside the cab with just what they post there

 

[Ron H]

@Ron H

ammeters are same hazzarous than the car itself:
-a car is a time bomb carrying a tank full of gas which can explode anytime with all the electric stuff.
-a car without brakes is able to kill ppl ( inside and outside )
-a car which blows a tire could make you loose control and kill ppl
-a car with bad timing can get backfiring through the carb and get on fire everything. In fact is easier that could happen and more common to than get your car on fire due the ammeter failure


so, same as get the correct timming, replace brake pads, checke brake fluid lines for leaks and check your tires, the electrical stuff, including ammeter has to be checked, mantenienced and understood how it works to prevent failures



Madelectrical stuff about ammeters is mostly full of BS. They are attacking incorrectly the real problem, aside they say with their mod the main splice is being moved to the engine bay, which is false. There is no way to change the main splice from inside the cab with just what they post there

We had chatted a while ago about my '63 why bypassing the BH was a safer idea. I gathered that the connection at the BH deteriorated from age/corrosion causing the electrical tiger here to escape. It wasn't the best design for the ages that Chrysler changed in the 70's. Gauge terminals on the old systems can deteriorate as well as I've researched, not as common as the BH issue but a failure can be huge.
https://www.allpar.com/history/mopar/electrical.html

 

[Nacho-RT74]

Sure I have sent you emails with diagrams showing many options about how to bypass bulkhead. But be confident about the ammeter once is checked good. You won’t have any problems after get a good alt able to keep sourcing at iddle

the bulkhead deal and the ammeter deal are two related problems but one doesn’t affect the other.

 

[383man]

@383man

I meant a shunted ammeter will get same result on a charge/discharge reading! Or 0 reading. Diagnosis based on its reading is the same. Then we can discuss or be agreed or not on the load actually handles or accuracy, but readings will mean the same on both kind of ammeters, shunted &/or full load

Shunted ammeters were began to use not because "customers claims" but because get a "safer" way to read the load status installed on cluster. It is less sensitive to the small flickering but not necesarilly less accurate on an average reading. Shunted ammeters are indeed the standard system on the testing procedure tools for loads.

Plus, most of the shunted ammeters are now rated to read +/- 60 amps, where the +/- 3 or 5 amperes reading will mean less needle move, so is harder to get a noticeable move with the same load demand

Let's also think cars began to get more electrical devices as standard option so alternators output began to be higher. Since 75/76 most of the 30-45 amps alts if not all were gone, and 50-65 amps began to be the standard. Not by casuality same moment the shunted ammeters floated on. With higher outputs alts, also the flickering on ammeters is reduced. Several small upgrades here and there makes a bigger and better result.

With my "78 amps" alt ( and I say "78 amps" because it got 100 amps decal on it but I seriouslly doubt it ) using the full load amm on my 74 I press brakes and ammeter doesn't even flicks at day light. On nights just small hard to notice flick ( but I have halogens headlights ). So is not necessarily a deal about being shunted or not, but the load feed/recovery capacity of the alt along with correct paths and a good regulator with good wiring too to get a fast response to the added load on that moment.

View attachment 981867 View attachment 981868 View attachment 981869

I changed the big pulley it came of course for the smaller pulley

I basically agree with you on everything but it was just my point from working on the cars back in the 70's how when they started using the shunt type in Mopars and Fords as I worked at Ford dealer a few years also that they barely ever moved in normal operating when the battery and charging system are working fine. As to the series style that Mopar used for many years up to about 1974 I believe that would move a good bit when driving even with everything working good. I just meant they definetly acted different. I did not care for the fact that the shunt type did not move much right away if a car stopped charging. They did not really tell the driver as much to me back then since they just did not move much as I think they had to much of the load going through the shunt and did not get the % just right of how much the gauge should carry related to the shunt. But to answer your question now as I thought you were trying to fool everyone but I say Yes the car is charging and working normal when the amp gauge is staying in the center since its not discharging or overcharging its doing just what it should. Ron

 

[Nacho-RT74]

well after 3 days is time where I think votes came out pretty well ( 83,9% thinks it works... I though on a worst result ) will advance this file from the Chrysler tech files somebody posted in the past and I saved. This will give you the answer not just posted by me ( what you could very well not trust ) but by the literature.

which supports what 72RoadrunnerGTX makes mention on the vid he posted to be checked at minute 12:10

 

[Nacho-RT74]

to be more graphic... this is what it means a 0 reading on ammeter with engine running, how the load goes from an alt working and correctly charged battery.

#1

Since batt is charged, won't claim load to get recharged. The batt is like a baby. Will suck milk while is hungry. Once is full won't cry for more load. So the ammeter won't get through it any load to the batt.

 

[Nacho-RT74]

with engine off ( or an unoperative alternator ) this is what happens, and the ammeter reading

#2

 

[Nacho-RT74]

with a discharged batt and engine running ( with a good operative alternator ) this is what happens


#3

or this if the alt gets poor capacity, RPMs are too low or battery is getting allmost full, but alt still able to hold the car loads AND the batt demand to get recharged


#4

The car load demand it keeps on same rate. But the extra capacity for load is requested by the batt to get charged. THIS IS THE ONLY LOAD THE AMMETER WILL SENSE, not the full alternator load capacity. And this gets its own limit, because amperes can't be pushed in by the alt if the batt doesn't suck it. Aside this the batt gets its own chemical process which CAN'T BE FORCED/PUSHED IN no matter if the alt is able to give more than the batt will suck

 

[Nacho-RT74]

now, if your alt is not being able to hold the car load at iddle, the batt will provide what the alt is not able to, so we get this:


#5

Note I tried to represent the load by the arrows thickness, being proportional to what happens on every stage.

 

[Nacho-RT74]

Our cars, by the lack of power from factory alternators ( and abused electrical systems ) tipically swings between #4 and #5... and giving RPMs, is able to reach the #3 if our car got lot of time staged on #5. This is the situation we must save, and this is the situation which burns the bulkhead. A bulkhead terminal ( Packards ) able to hold around 25-30 amps, maybe even 40 peaks, but where a discharged batt this load can be increased up to 50-60 amps ( just 15-25 or at some circunstances 30 amps just to the batt ). Thats around the double the packard terminals are able to handle.

How do you save this ? with an alt able to source all the car load demands at iddle or minimal RPMs as posible, and a safer path between alt and ammeter. This also will save the car from get the battery discharged, hence the ammeter getting loads ( coming or going ) Many options to make this safer paths, but I won't get in into this now. This thread was just made to show what it means the ammeter and its reading.

So now, you can see how is more dangerous to have a low capacity alt, than a high output alt. Your car won't suck more power just because gets an alt able to source it. It will suck just what it needs. Amps can't be pushed in.

and once again...

DON'T ADD ANY ACCESORIES TO THE BATT POST OR STARTER RELAY. THE AMMETER WILL READ IT AS A CHARGE AND WILL STRESS THE SYSTEM BETWEEN AMM AND BATT EVEN MORE without need for that.

Most of the damaged ammeters and burnt spots at red wire on bulkhead come from this job made along the years.

Also... if you are adding accesories, the alternator is the first power source to be upgraded, NOT THE BATT. The batt initially is just made to start up the engine and provide ocasionally some low loads peaks. But a bigger capacity battery will make a harder job for the alt to keep it charged, so more time giving loads to the full charging system, aside the car loads demand.

Is a fact the ammeter represent somekind of resistance to the circuit, same as any terminal around. So is true with constant loads going throught ( no matter if coming or going ) the ammeter will transform in into heat. BUT if you save the lack of load from alt, the ammeter barelly will work so it won't be a "problem" anymore.

So opposite what ppl tends to think, a bigger alt load capacity it becomes on a SAFER stage for the ammeter