How many AMPS in your alternator?

[RJRENTON]

The AMP rating of an alternator is determined by design, not by the amps "in" the unit. The total amp that could be produced is a function of the stator winding wire size and slot depth to make more space for wire. The diode assemblies change the stator current to DC current and the units overall capacity is also limited to the rectifying capacity of these diodes. The rotor's windings determine how strong the magnetic field is generated and in turn how AC current is produced and ultimately made into DC. How the unit is controlled (1like the original design, 2 wire units begining in 1970 or the 1 wire unit with the internal regulator) is not a significant point. What is important is what total capacity for the electrical system. 100 amp units will only supply what the connected load requires. It will not supply 100 amps all the time, just if/when the load requires it. Also, bear in mind that a higher capacity alternator will require higher horse power from the engine. (and possibly more belts to transmit that horsepower). The speed (RPMs) that the alternator is turning will also affect its output (both voltage and current). Usually the maximum output is design controlled by the impedance of the stator windings (and possibly the thermal capacity of the internal diodes). Impedance is similar to resistance but is measured differently as its affected by the frequency (speed at which the unit is turning) Mopar used to use the old Leece-Neville units when high electrical loads were needed. What ever unit is ultimately selected, must be determined by the owner based on the connected load requirement and perhaps appearance of car /engine.
Cheers,
RJ Renton

 

[440roadrunner]

No need bypass the ammeter and convert to voltimeter like madelectrical website suggest with an alt upgrade. Just upgrade wires running to ammeter, bypassing bulkhead terminals... With a powerfull alt and EVERY ACCESORY ADDED sourced CORRECTLY from alt side you'll be making the things correct. Ammeter won't sense any big charge or discharge reading anymore.

On ammeter cars is a BIG MISTAKE source any extra device from batt.

Still preaching the same tired speech I see. I like ammeters too, but they "just don't work" when you start running 80-100A alternators on a stock ammeter. I've seen LOTS of them melted, JUST LIKE the Mad site photo shows. Why is it then, "Nach" if ammeters "were" so great, that EVERY SINGLE CAR MAKER including Chrysler got rid of them? Even Ma started to around 72 or so in the Furies and other big cars...........started going to EXTERNAL SHUNT ammeters.

 

[Nacho-RT74]

ok, tell to my car I'm wrong ( since maybe 6 or 7 years ago, maybe more, I can't recall ), being a daily driver using AC allmost 70% being driven and safe with stock full load ammeter... yes, maybe I'm wrong.

Yes we got shunted ammeters on mid 70s but still running unneficient alternators, which took around 10 years more by Chrysler to be better suited for the car demands, when they equipped 80 amps alts on cars.

I'm agreed shunted ammeter on cars are a great upgrade, but since there is not shunted ammeter for pre 75 Mopars, you can make it work still safe making a correct charge balance on full load ammeters ;)

But yes, I'm still wrong and My car will get fire soon.

Why you keep despiting my own experience ? where by the way I'm not the only one who has make it!!!

Why don't you try it by yourself to confirm what I say and begin to respect my experience ?


Just getting an alt able to give the car demand power at the lower RPM as posible ( iddling if posible ) and bypassing the bulkhead terminals ( actually just the black wire could be even enough ) will be enough still with stock full load ammeters

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of course every step needs to be made correctly. Adding relays upgrades will get you a better upgrade ( lights and blower ).

Guess what ? I'M FEEDING MY RELAYS FROM AMMETER STUD ON BLACK SIDE because all my relays upgrades ( 6 in total ) are inside the cab to keep clean the engine bay... believe it ? or not ? and my ammeter keeps cold ( I keep checking it, an overheated ammeter gets the heat up to cluster bezel!!! ), barelly gets high reads!!!

But of course you don't believe me.

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One thing more:

My mom WHO IS A GRRRRRREAT CHEF adds salt to the potatoes before get fried, but mostly of ppl adds it after get it fried.

Have you tried how they taste with salt added before being fried ?

but hey.. YOU NEED TO KNOW WHEN is the right moment add the salt before be fried!!!

AND I WORKED AT MCDONALDS WHEN I WAS YOUNG!!!

Think on that!!!

 

[texas69bee]

Wtf?

 

[383man]

I will say ammeters are a good to use for moneriting the charging system. I believe Mopar went to the shunt type ammeter's around 1972 as I know my mom's 73 Dodge wagon had a shunt type ammeter. You can tell real easy if you pull the headlites on with the eng and key off and the ammeter neddle does not move then you can be pretty sure its a shunt type. The Shunt type are a good idea since they only carry about 1/10 of the load if they use the correct wire size. I honestly feel most manufactors dont use an ammeter because its more work and wireing to use an ammeter since they are wired in series and its much easier for the manufactor to just build the wire harness for their cars as they can add a voltmeter in anywhere you have good key on volts or they can put a simple idiot lite in it. As a tech when I diagnose charging problems the first thing I do is put an ammeter and voltmeter on the car. And I prefer to use my ammeter that hooks in series with the output wire over the type that use a shunt you clip over the wire as I feel that type is not as accurate. But the ammeter tells me alot more then a voltmeter will when I need to know just how much the alt is putting out.
The ammeter bypass is a good idea because on our older Mopars all the output current has to go through the bulkhead and through the ammeter in the opposite direction so the ammeter needle will show a charge but after alot of years the bulkhead connections get corroded and when you upgrade the alt you may be putting 50 to 90 amps through the ammeter that was built to handle up to about 60 amps tops. So I agree its a good idea to bypass it and just put a simple voltmeter in it.

I really feel to put a shunt type ammeter back in the car would be more accurate then the voltmeter but its alot of work and wireing to put an ammeter back in and its so much easier to just add a voltmeter that hooks in parallel. Ron

 

[440roadrunner]

Everything is NOT fine, and "Ma" knew that a long time ago. "The big cars" (sea barges) got shunt ammeters long before say, "A" bodies around 75? for them

Proof? It's called "police, taxi, fleet" wiring, and was a CHANGE when equipped with optional 60-65A alternators. The amp gauge wires BYPASSED the bulkhead connector, a positive move


I always post the Mad Electrical article which is an EXTREMELY good writeup

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

"The why"

First there is age. These girls ain't gettin' any younger, and things like terminals / connections / switches do deteriorate in 40-50 years. They were marginal at best, "designed" for a 35-40A alternator, and NO big extras like big stereos, fans, pumps, electric water pumps.

Second, is the ammeter. "Depending on the vehicle" (look at the photo on Mad)

Some clusters have a PLASTIC housing, and the ammeter assembly all clamped together via the stud nuts. When the plastic got a bit warm, things loosened up, and that photo is the result. I've seen LOTS of those on pickup truchs in the '70's LOTS.

The ammeter construction is part of this same problem. There is really nothing to hold the ammeter together. Some of them are "sort of" crimped together, but "most" the studs are loose in the shunt. This means ANY loosening of the nuts allows a bad connection either at the wire ends or at the stud - to - shunt, or a combination.

The infamous bulkhead / firewall connector. This thing uses common 1/4" flat connectors (Packard 56) which WERE NEVER designed for the kind of amperage they must carry. I used to maintain, and repair heat pumps, AC and electric furnaces. I've seen LOTS and LOTS of failures with these 1/4" quick connectors, and electric furnace elements ONLY DRAW a nominal TWENTY AMPS.

Below is a VERY typical electric furnace controls setup and all the connections you see there are this type. THEY DO FAIL and again, at TWENTY AMPS

Conclusion? Yes you could make a PARTIAL ammeter shunt, but unless you figure a way to install a LATER model "external shunt" ammeter, it simply is not worth the hassle.

External shunt ammeters aren't all they are cracked up to be, either. Some of the Fords were VERY numb. In two of my Rangers, you had to STARE intently at the ammeter when turning the headlights on "to see if it moved." In other words it took a lot of power to show any movement on the needle.

This was a problem in earlier Ford pickups, as well. Both "ma" and Ford used part of the harness itself as a shunt, and I believe GM did, too. Nothing really wrong except the gauge and length of the harness itself CHANGES the shunt value. So it would take a bit of engineering to "upgrade" wiring if need be, to get the damn thing to indicate decently.

 

[Nacho-RT74]

madelectrical states a falste statement... they saye are moving the main splice outof the cab with their mod, which is not truth... the main splice is still inside the cab and thre is no way to move that making what they did. The main splice Is the one which feeds the fuse box, ign key and lights too.

I'm not saying the ammeter couldn't melt the cluster, loose it own studs from the internal gauge plate, crack the isolators etc... I'm not saying the bulkhead 56 packard terminals are the propper one. Everything on stock form BEING THE POOR ALT OUTPUT ALT the first fail on this design, then the weak terminals at bulkhead are the main problems on the stock design. What I'm saying is whit an alt able to feed all the car demands at iddle ( no matter if 100 amps o 1000 amps ) will save you the back and forth ammeter bounce, and the bulkhead bypass, no matter if running a parallel ( keeping the stok ones if still in good conditions ) or removing stock ones and just using ones at a side of the bulkhead, is SIMPLY ENOUGH to keep safe your car. No need for more mods or magic tricks. Not even needed a shunted system, stock system with the propper upgrades is simply enough and I have prooved that. Several guys more have tried the same with same sucess.

If you get a good alt the battery won't ever feed the lack of load the alt is not able to give iddling at the OTHER side of the ammeter, When this happens, giving gas to the engine alt will recharge what the battery lost on te previous stance once again croosing through the ammeter. This is what the back and forth needle movement tells you. Saving the load going through the ammeter will save you from heat there, so no more problems there. With this, the only next problem to deal are the bulhead terminals which ACTUALLy making just the alternator side should be enough, but, better make it on both sides ( batt and alt ) in case of an alt failure. Done.

Why this is so hard to understand and accept ? and once again why you despite my own experience on my own car with this mod made maybe 8 or 9 years ago? and my car IS ( actually is at body job, but was ) my DRIVER car, using AC every season of the year ( I live in tropic ), being the AC blower the most load sucker device in all the car ?

I'm not despiting what you say, just exposing what is not necesary to make if you want to kep your car working like factory did, keeping your ammeter working as ammeter and not converted to voltimeter.

then if ppl preffers make those ( unnecesary ) modifications, go ahead... but let him know there is an easier and trustable way to do it keeping everything like factory did makes no hurt.

If ppl want more, here is a GRAPHIC way I posted all the load runs through the charging system and how it works. If you made to understand this, you can't say I'm wrong. And my car with stock 40 amps ammeter and actual 100 amps alternator ( although it seems to be more like 80 amps ) have prooved what I exposed on graphics on my STOCK FULL LOAD ammeter system. I even recorded a video showing what aammeter shows on my system just that can't find where is to post it. Shows EXACTLY what I did on diagrams

http://www.dodgecharger.com/forum/index.php/topic,33574.0/all.html

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and, once again, there is a failure added by car owners on their ignorance about how the charging system works on ammeter equipped cars which is feed any extra added accesory from BATTERY side... totally wrong what adds stress on a system prone to failure from factory underloaded designed system.

ANY ACCESORY MUST BE SOURCED FROM ALT SIDE OF THE CHARGING SYSTEM, fuse box is like that, factory accesory sources are also on that way ( from ign switch ). If you need more BATT sources than factory gave you on stock harness, just need to add a junction point OR use the ammeter stud, buth any of both on ALTERNATOR side of the game.

wondering how many cars got a premature failure on their cars because of this ? I bet the battery positive lead must be getting LOTS of wires there added on these cars... and still on stock poor alt.

Now everything of this is exposed, it at each own to choose what they want to make.

 

[Yatzee]

When it comes to amp output you can't beat a Ford 3G 130 amp alt. Easy to mount, easy to wire and no outboard regulator. With high beams on (four headlites), heater on, electric fuel pump running, 30 amp cooling fan running,brake pedal depressed (four 1157 bulbs) and Interior lites and radio on, it puts out a constant 14.2 volts on the Autometer gauge with no waivering of the needle even when the turn signals are activated. How well does your charging system handle this type of situation? "Time for an upgrade" you say?

 

[67 coronet]

take it from some one who had it happen,TWICE!do not keep the original amp meter.had a 68 charger dash metdown and lost an entire 77 pickup because the amp meter melted.i was driving,i watched it happen both times.make sure you have a good eng ground to frame as well.can cause flickering lights if ground sucks.

 

[440roadrunner]

madelectrical states a falste statement... they saye are moving the main splice outof the cab with their mod, which is not truth....

Again you don't know what you are talking about. The way Mad did their project REMOVES the alternator load on the internal wiring in the car. Many guys run a direct line from the alternator to the battery. If that is protected, even better

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If you get a good alt the battery won't ever feed the lack of load the alt is not able to give iddling at the OTHER side of the ammeter, .

Completely false thinking and logic. Absolute nonsense. No vehicle on the planet is currently so designed. I'll ignore the poor English.

 

[Nacho-RT74]

whatever!!!

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MaMopar just made the mistake on the loads required to make it work safe allong with the good connection to save from fails, but not on HOW IT WORKs the system and the ammeter reading. Which is not actually an ALTERNATOR gauge, is actually a batt gauge. Alternator doesn't get charge or discharge, because they are not acumulators. Is not posible to get a discharge from them... ( another misundertanding to car owners )

all the loads are taken from alternator side of the charging system, and when alt is enough to feed the car load and batt is fully charged, the needle will stay in center which doesn't mean engine is off and there is not load on the system, just the batt is not being charged or discharged. No reading there it means no load going through, so no heat there.

Try it. I alredy did it!... will try to post the video once I find it.