Will do. Thanks Del.....and all the rest of you as well. It's much appreciated.
Charging System Question
- Thread starter RustyRatRod
- Start date
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I've been working on some of these rebuild mysteries and this is may be the source of many problems.
Remember way back I said that it seemed like the regulators failed when using a revised squareback?
I was talking about the transistorized ones that look like the Mopar Performance regulator. Standard's tech person couldn't tell me anything about its specs but it I'm more convinced now that most of the regulators weren't made to handle field currents over 5 amps.
It looks to me like alternator rebuilders use just one rotor for replacement. The current draw on my 10 yr old Carquest 7024 was just over 5 amps. I figured the rotor was bad. But looking at the alternator sheet @Dana67Dart posted, this may be typical for newer rebuilds.
They're using a rotor wound with bigger wires or whatever that is lower resistance and higher draw.
I think this may be the root of many problems we're seeing. Its killing the VRs, and its almost doubling the load on the wiring. Most A-bodies only got an 18 ga wire to the regulator, and maybe the same to the field. My point is now those 18 ga crimps are subject to 5-6 amps or more instead of 2 to 3 amps. Not even getting into what that might be doing to the mechanical regulators.
Maybe I'm jumping to conclusions but wanted to share so you guys can look out for this.
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from the '73 FSM. Slip ring to slip ring the rotor should be 3 to 4 ohms at room temperature.
The rotor in Carquest 7024 sq back measured 1.7 ohms. This drew 5.6 amps at 12.5 Volts when tested on the car per FSM. It had one bad diode - not sure that magnetic field makes much of a difference but I will retest when its back together.
The rotor in the Tuff Stuff Revised Swq back: 1.7 Ohms
Rotor in a '70-71 alternator, Reliant 7015 rebuild from junkyard 22 years ago: 3.5 ohms
NOS late 60s rotor: 3.7 Ohms
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It's funny you mention that, because the regulator that's on it is a fairly new Borg Warner "Select". That's secret language for supposedly their "best". Still has the two wound wires on the back, but I don't know what's in it. I got the old style NOS type coming.I've been working on some of these rebuild mysteries and this is may be the source of many problems.
Remember way back I said that it seemed like the regulators failed when using a revised squareback?
I was talking about the transistorized ones that look like the Mopar Performance regulator. Standard's tech person couldn't tell me anything about its specs but it I'm more convinced now that most of the regulators weren't made to handle field currents over 5 amps.
It looks to me like alternator rebuilders use just one rotor for replacement. The current draw on my 10 yr old Carquest 7024 was just over 5 amps. I figured the rotor was bad. But looking at the alternator sheet @Dana67Dart posted, looks like this may be typical for rebuilds.
They're using a rotor wound with bigger wires or whatever that is lower resistance and higher draw.
I think this may be the root of many problems we're seeing. Its killing the VRs, and its almost doubling the load on the wiring. Most A-bodies only got an 18 ga wire to the regulator, and maybe the same to the field. My point is now those 18 ga crimps are subject to 5-6 amps or more instead of 2 to 3 amps. Not even getting into what that might be doing to the mechanical regulators.
Maybe I'm jumping to conclusions but wanted to share so you guys can look out for this.
-----------------------------
from the '73 FSM. Slip ring to slip ring the rotor should be 3 to 4 ohms at room temperature.
The rotor in Carquest 7024 sq back measured 1.7 ohms. This drew 5.6 amps at 12.5 Volts when tested on the car per FSM. It had one bad diode - not sure that magnetic field makes much of a difference but I will retest when its back together.
The rotor in the Tuff Stuff Revised Swq back: 1.7 Ohms
Rotor in a '70-71 alternator, Reliant 7015 rebuild from junkyard 22 years ago: 3.5 ohms
NOS late 60s rotor: 3.7 Ohms
Less wire would increase the amperage draw too (Lower resistance)
I assume increase in amperage draw equates to stronger magnetic field which should increase the amprage output.
67Dart273
Well-Known Member
Sadly that is not necessarily true. There's a term in transformer winding (which I can't remember) that describes something to do with "amp turns." What it kinda comes down to is that the size of the wire against how many windings determines the field. Bigger wire of course means less room for windings. More windings of smaller wire means less current. It's a balancing act
I found this
https://forum.allaboutcircuits.com/threads/amp-turns.62593/
KitCarlson
Well-Known Member
Field intensity increases with amp-turns. That is product of current and winding count. There is a limit, due to saturation of magnetic circuit.
Increased field, increases alternator output voltage, but output current, is load related.
Regulator action controls field current dynamically, and regulates voltage as necessary for RPM, load, and voltage drop variations.
Increased field, increases alternator output voltage, but output current, is load related.
Regulator action controls field current dynamically, and regulates voltage as necessary for RPM, load, and voltage drop variations.
So one limitation is saturation - I assume this is on the field - and then there is the limitation of the stator.
On these aftermarket rotors, if they are making a stronger magnetic field, then the regulator has to be making and breaking the field more often to try to control voltage.
It seems the industry has decided that its OK to use the '60 amp' rotor for everything.
The Chrysler parts books I've looked at so far show indicate for repair any alternator all alternators got the same replacement rotor except a 60 amp alternators.
For repair the 60 amp alts have their own rotor. There probably was a good for reason for that. One of these may be the current draw.
With the squareback Dana bought, the test sheet shows 6 amps. Way out of spec. per the FSM.
The same sheet shows it is capable of producing something like 70 amps (I forget the voltage and rpm) but at what cost? Does it 'turn on' at idle rpm? and even if it does, what's it doing to the circuit?
There's some Speedtalk posts from 2014 by 'BC Johnny' where he was discussing the ways alternators produce power. Seemed to know what he was talking about. Time for a reread.....
How Alternators are "Upgraded" - Don Terrill’s Speed-Talk
On these aftermarket rotors, if they are making a stronger magnetic field, then the regulator has to be making and breaking the field more often to try to control voltage.
It seems the industry has decided that its OK to use the '60 amp' rotor for everything.
The Chrysler parts books I've looked at so far show indicate for repair any alternator all alternators got the same replacement rotor except a 60 amp alternators.
For repair the 60 amp alts have their own rotor. There probably was a good for reason for that. One of these may be the current draw.
With the squareback Dana bought, the test sheet shows 6 amps. Way out of spec. per the FSM.
The same sheet shows it is capable of producing something like 70 amps (I forget the voltage and rpm) but at what cost? Does it 'turn on' at idle rpm? and even if it does, what's it doing to the circuit?
There's some Speedtalk posts from 2014 by 'BC Johnny' where he was discussing the ways alternators produce power. Seemed to know what he was talking about. Time for a reread.....
How Alternators are "Upgraded" - Don Terrill’s Speed-Talk
Re: How Alternators are "Upgraded"
Post by BCjohnny » Sat Nov 22, 2014 6:34 am
Within a given frame size, simplistically, by increasing the cross sectional area of the conductor, in this case the stator windings, the amperage output is similarly increased. This can be done by increasing the number of turns of wire but more commonly by increasing the gauge with round section wire, or less commonly, going to 'flat-wound' large section wire (CAV, Denso etc). 'Re-wiring' the stator, for instance going from a star to delta wound arrangement, are other tricks manufacturers resort to, as is adding a 'tap' to star connected stators to create a four wire rectifier (~10%).
Upping the rotor magnetic field strength, again by increasing the number of turns, or increasing the field current, as Delco did with some european models by going from a 3amp to 7amp field, also give greater output to a lesser extent, as does reducing the rotor/stator air gap (obvious production limitations). Increasing the rotor diameter and 'slimming down' the stator width to maintain frame size, as Bosch did with certain 70/80amp K1s, is also an option.
Drawbacks..........As alternator efficiency is fairly constant across the better contemporary manufacturers, although in all cases goes down with machine temperature (alternators are most commonly rated 'hot'), increasing the output creates more 'waste' heat, which affects all components, but the rectifier to the greatest extent. Higher rated diodes, more efficient heatsinking, and cooling flow are required. In this last respect modern internal fan (IV) machines which cool from the inside out, as opposed to older front fan draw through types, are better capable of dealing with this. Or, as OE outputs grow, jacketed machines plumbed it into the cooling system are becoming more common. Increasing field strength means higher rated parts.
Also, again within a given frame size, increasing ultimate output is usually at the expense of lower speed output. Much like a highly tuned engine, the power curve is more peaky. The 'cut-in-speed' (CIS), when the machine starts charging, is often higher too.< end snip>
This struck me
output creates more 'waste' heat, which affects all components, but the rectifier to the greatest extent.
because a diode check indicated the ground rectifier on the Carquest 7024 was damaged.
When I opened the alternator up and took it out, didn't need a meter to see what had failed.
Nice thing about the square back is the rectifiers can be checked with a meter without disassembly, sometimes even on the car.
Post by BCjohnny » Sat Nov 22, 2014 6:34 am
Within a given frame size, simplistically, by increasing the cross sectional area of the conductor, in this case the stator windings, the amperage output is similarly increased. This can be done by increasing the number of turns of wire but more commonly by increasing the gauge with round section wire, or less commonly, going to 'flat-wound' large section wire (CAV, Denso etc). 'Re-wiring' the stator, for instance going from a star to delta wound arrangement, are other tricks manufacturers resort to, as is adding a 'tap' to star connected stators to create a four wire rectifier (~10%).
Upping the rotor magnetic field strength, again by increasing the number of turns, or increasing the field current, as Delco did with some european models by going from a 3amp to 7amp field, also give greater output to a lesser extent, as does reducing the rotor/stator air gap (obvious production limitations). Increasing the rotor diameter and 'slimming down' the stator width to maintain frame size, as Bosch did with certain 70/80amp K1s, is also an option.
Drawbacks..........As alternator efficiency is fairly constant across the better contemporary manufacturers, although in all cases goes down with machine temperature (alternators are most commonly rated 'hot'), increasing the output creates more 'waste' heat, which affects all components, but the rectifier to the greatest extent. Higher rated diodes, more efficient heatsinking, and cooling flow are required. In this last respect modern internal fan (IV) machines which cool from the inside out, as opposed to older front fan draw through types, are better capable of dealing with this. Or, as OE outputs grow, jacketed machines plumbed it into the cooling system are becoming more common. Increasing field strength means higher rated parts.
Also, again within a given frame size, increasing ultimate output is usually at the expense of lower speed output. Much like a highly tuned engine, the power curve is more peaky. The 'cut-in-speed' (CIS), when the machine starts charging, is often higher too.< end snip>
This struck me
output creates more 'waste' heat, which affects all components, but the rectifier to the greatest extent.
because a diode check indicated the ground rectifier on the Carquest 7024 was damaged.
When I opened the alternator up and took it out, didn't need a meter to see what had failed.
Nice thing about the square back is the rectifiers can be checked with a meter without disassembly, sometimes even on the car.
KitCarlson
Well-Known Member
At best, automotive alternators are 60% efficient. Efficiency could be increased some, with synchronous rectification, using mosfets instead of diodes. That would add cost and more parts. Permanent magnets, instead of electromagnetic field, and more complex power conversion instead of simple field regulation.
If efficiency is important, high power loads, like electric fans, are best handled with belts and thermostatic clutches.
If efficiency is important, high power loads, like electric fans, are best handled with belts and thermostatic clutches.
Back to our cars.
The point is that whenever the regulator senses voltage below set point its going to directly connect the wires.
Current flow on a '64 with just engine running would look like this.
Now we install an ORielly 7007 '60 amp' alternator that draws 6.2 Amps (at 14 Volts? )
What's this doing?
Besides putting more load on the field wires and connections, its diverting more of the alternator's output just to power the field.
Maybe that's OK, but maybe not at idle rpms when the battery wants to be recharged, and the brakes lights are on, along with other stuff?
I think at the very least its damaging regulators not designed for that much load.
@RustyRatRod
The point is to do the field draw test.
First make sure there isn't a short to ground.
Then loosen the alternator enough you can turn the pulley by hand.
Using a meter that can measure a few amps, set it to the 10 amps scale and alligator clip it like this.
Be super careful not to let either clip touch ground.
The point is that whenever the regulator senses voltage below set point its going to directly connect the wires.
Current flow on a '64 with just engine running would look like this.
Now we install an ORielly 7007 '60 amp' alternator that draws 6.2 Amps (at 14 Volts? )
What's this doing?
Besides putting more load on the field wires and connections, its diverting more of the alternator's output just to power the field.
Maybe that's OK, but maybe not at idle rpms when the battery wants to be recharged, and the brakes lights are on, along with other stuff?
I think at the very least its damaging regulators not designed for that much load.
@RustyRatRod
The point is to do the field draw test.
First make sure there isn't a short to ground.
Then loosen the alternator enough you can turn the pulley by hand.
Using a meter that can measure a few amps, set it to the 10 amps scale and alligator clip it like this.
Be super careful not to let either clip touch ground.
67Dart273
Well-Known Member
As long as the alternator can produce more power than that being consumed by the field, it is still a net gain. The field wiring and regulator should be designed to accommodate that power If the alternator somehow has a heavier field draw (due to rebuilder or later alternator changes, etc) that is "not the fault" of the regulator design. There ARE other "generic" grounded field regulators that will work as well. Too bad the solid state one that was around seems to be now obsolete, I cannot remember the part no. It's the parts store version of the "blue" "race" regulator "constand voltage." People get all excited about that term but the reality is, ANY voltage regulator is supposed to be --by definition-- "constant voltage"
https://www.forbbodiesonly.com/moparforum/attachments/20200614_130820-jpg.1124226/
https://www.forbbodiesonly.com/moparforum/attachments/20200614_130820-jpg.1124226/
67,
You raise a good point about 'constant' voltage control from the reg.
When I bought the Mopar elec ign upgrade back in the 1970s, you were supposed to also buy the 'new reg'. I often wondered why & what would happen if it wasn't used.
You raise a good point about 'constant' voltage control from the reg.
When I bought the Mopar elec ign upgrade back in the 1970s, you were supposed to also buy the 'new reg'. I often wondered why & what would happen if it wasn't used.
Did any of the wires or components smoke when you were testing or fixing the charging problem????
If so, you need to put the smoke back in the system for it to charge properly....
Electronics run on smoke... If you let too much of the smoke out, you have to replace it before it will work again....
If so, you need to put the smoke back in the system for it to charge properly....
Electronics run on smoke... If you let too much of the smoke out, you have to replace it before it will work again....
Damn. I give up.
Nuthin. I got it fixed. Put a NOS old style regulator on it ant it's charging great.
I just told yall off the bat, I'm a dumbass with electrical and yet yall still turn it into a science project. I don't understand this ****. I need layman's terms ant it always goes sideways. But it's fixed and that's all that matters.
BS. Don't tell me you can't disconnect the green wire from the alternator and connect a multimeter that reads amps like this
Thought I had a photo on the car.
But field current measurement is not complicated.
You can do it on the bench as well.
Ignore the mess. Grounded field alternator.
1. Connect the alternator housing to ground. On the car that's already done by being mounted.
2. Set the multimeter. For this one it means plugging one of the leads into the 15 amp position and turning the dial.
3. Connect one lead of the the multimeter to the power and the other the alternator's field terminal.
Try to turn the pulley while taking the reading. Disconnect. Done.
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