Help with alternator troubles

[TWS67'Fury]

Help I've replaced vg, alternator, and still no charging well it charged but very very slowly at the battery I'm getting 12.51v and it slowly increases to 12.6: and stops charging I've checked continuity ect. I don't know what to do. I will mention it is an aftermarket 60amp dual feild. I've grounded one of the fields and plugged the other into the feild wire and I'm still only getting less than .01v charging. If I read from alternator charge (black wire) and feild (green) I get heavy fluctuations between 13.9-14.8v. Help!!!!

 

[Davea Lux]

Help I've replaced vg, alternator, and still no charging well it charged but very very slowly at the battery I'm getting 12.51v and it slowly increases to 12.6: and stops charging I've checked continuity ect. I don't know what to do. I will mention it is an aftermarket 60amp dual feild. I've grounded one of the fields and plugged the other into the feild wire and I'm still only getting less than .01v charging. If I read from alternator charge (black wire) and feild (green) I get heavy fluctuations between 13.9-14.8v. Help!!!!

What year car and which voltage regulator are you using? If this is the '67 in you moniker, the '67 regulator probably will not work with with an after market alternator. Check that you are getting power to the alternator field. You are correct that one of the field wires is hokled to ground, the other is hooked to battery voltage to complete the circuit.

Dave

 

[Big_John]

You are correct that one of the field wires is hokled to ground, the other is hooked to battery voltage to complete the circuit.

The other field wire needs to be connected to the voltage regulator. That does give it battery voltage, so you are correct in that regard, just gotta go through the VR first.

I'm sure that's what you meant... Just making it clear.

 

[Big_John]

Help I've replaced vg, alternator, and still no charging well it charged but very very slowly at the battery I'm getting 12.51v and it slowly increases to 12.6: and stops charging I've checked continuity ect. I don't know what to do. I will mention it is an aftermarket 60amp dual feild. I've grounded one of the fields and plugged the other into the feild wire and I'm still only getting less than .01v charging. If I read from alternator charge (black wire) and feild (green) I get heavy fluctuations between 13.9-14.8v. Help!!!!

Here's how you test it.

Take a voltage reading at the battery just for reference, car not running.

Disconnect the other field wire from the alternator and make a jumper wire that goes from the connector on the alternator to the output terminal on the alternator. This bypasses the voltage regulator.

Turn on the headlights on high beam and start the car.

Check the voltage at the battery again. It should be 14-15 volts at minimum. If it's not, there's a problem with the alternator. If there is, the problem is either the voltage regulator or the wiring to the VR.

Don't run the car for long like this. Just long enough to check voltage.

This duplicates the FSM procedure except you are using the headlights to load the battery rather than the carbon pile. What we are doing is bypassing the VR to perform the test. The VR controls the alternator by completing the circuit in the field to battery positive.

 

[TWS67'Fury]

What year car and which voltage regulator are you using? If this is the '67 in you moniker, the '67 regulator probably will not work with with an after market alternator. Check that you are getting power to the alternator field. You are correct that one of the field wires is hokled to ground, the other is hooked to battery voltage to complete the circuit.

Dave

What vg do I use then I had to replaced the 67 vg for a new one same points style tho and on the vg I have the green fld wire going to one of the alternator fields and the other feild is grounded. Are you saying I hook both fields to the vg or not. I did what big-john said and determined that the alternator was bad just picked up a new one (this one seems to be better quality) I'm still unsure and feel like I'm doing something wrong.

 

[Big_John]

I have the green fld wire going to one of the alternator fields and the other feild is grounded. Are you saying I hook both fields to the vg or not.

You already have it correct. One field wire goes to the voltage regulator and one goes to ground.

The original 1967 alternator did this grounding internally. Your new alternator is actually built so it fits a 1970 and newer as is, and it fits 1969 and older with the extra field connection grounded externally with a jumper wire.

What happened was in 1970, they went to an electronic voltage regulator. That regulator controls the negative side of the field. Before that (like your car) the regulator controlled the positive side of the field.

Hope that helps.

 

[TWS67'Fury]

I get what your saying now. I put the new alternator in and for about 2-3mins it was charging I was reading 13.1-14.2 at battery I know it's low but it's higher than I've seen in a while. This is a picture of the vg I just replace and now took off it was full white on the bottom resistors when I put it on is the alternator too powerful for the vg? Do I need to go with the 60-100amp version? Or do I cut it out and go with a newer style vg. This problem went from a simple fix I thought to a blistering headache.

 

[Davea Lux]

You should use a voltage regulator that is rated at 60 amps. Since you already have a new unit installed, use it until if fails as you would rarely draw a 60 amp charge. I would keep a heavier unit as a spare just in case...Or you could install the heavier unit and keep the other as a spare, what ever you are comfortable with.

Dave

 

[TWS67'Fury]

You should use a voltage regulator that is rated at 60 amps. Since you already have a new unit installed, use it until if fails as you would rarely draw a 60 amp charge. I would keep a heavier unit as a spare just in case...Or you could install the heavier unit and keep the other as a spare, what ever you are comfortable with.

Dave

Here's the potential problem. I'm running 2 12s and before I hear the flack for "why would you do that to a classic" it what I wanna do. Anyway I wonder if the stock voltage regulator "burnt up" because of the large load from the subs and amp. Now granted they aren't running huge wattage (800w) compared to others (1500w+). I'm just confused because the first new alternator worked fine for about 2mth then I was driving and amp meter moved around a bit then no charging in fact slight discharging tested the voltage regulator and disassembled it and it was apparent it was shot. So I replaced it and nothing replaced alternator (faulty alternator) so nothing replaced alternator again and finally something for a few minutes then nothing again. Listen I'm a smart guy and have been trying my hardest to figure something that is wrong with this alternator/regulator. I'm getting close but I feel like maybe there is something I'm missing. I will add the only thing that I can tell has changed is the fact that I put in an electric choke and spliced the wire coming from ign side of the vr could that be my cause of no charging I have suspected it but idk there is a 10amp fuse inline so I can break the connection I notice a little change but not much I also noticed that when I put the voltmeter to the two contacts of the inline fuse I get high 13s haven't done much more testing. That should sum almost everything up. Sorry for the essay.

 

[Big_John]

Maybe the thing to consider is updating to a 1970 electronic voltage regulator.

It would involve a little wiring, but I think with your use, it might be less troublesome.

 

[Big_John]

You'll need a 1970 up voltage regulator. Available anywhere... Ask for a 1970 Chrysler at the parts store.

You'll need a plug. NEW VOLTAGE REGULATOR PIG TAIL PLUG HARNESS FOR MOPAR CHRYSLER DODGE PLYMOUTH | eBay

and a few feet of wire and a couple connectors.

 

[TWS67'Fury]

So I've bought the newer style vr and i took a picture of the old vr and i was wondering what to do with the blue wire going to the ign ballast i figure i just put the dgrn wire along with the green wire on the pigtail. And I'm assuming you want me to join the existing wire from the regulator to the ballast with a new wire from fld on alternator
Am i understanding correctly. Thank all of you guys for the help.

 

[Big_John]

So I've bought the newer style vr and i took a picture of the old vr and i was wondering what to do with the blue wire going to the ign ballast i figure i just put the dgrn wire along with the green wire on the pigtail. And I'm assuming you want me to join the existing wire from the regulator to the ballast with a new wire from fld on alternator
Am i understanding correctly. Thank all of you guys for the help. View attachment 595305

I'm not sure if I'm reading this right or not... Yes, you have to add a power wire that runs down to the alternator field. The better place is at the ballast resistor, only because it's a good spot that is switched with the ignition switch and not on all the time.

That fried green wire going to the old voltage regulator is bothersome though.

 

[thethee]

That fried green wire going to the old voltage regulator is bothersome though.

Looking closer at it, the violet wire beneath it is also not healthy looking. Probably wise to check that entire bundle before going further.

 

[Gerald Morris]

Here: Do yourself a BIG FAVOR and get a regulator from our own Mr. FuryGT:

Mopar Voltage Regulator - Electronic Solid State with Correct Restoration Look 724469250010 | eBay

He has a line on some GOOD solid state regulators from the Middle Socialist Republic!

Seriously, while I usually roast sino-products, these are the Exception. Get one, wire your alternator's second field lug to ground, rewire your charging harness with new stuff, over sized at least once, and you can kiss your problems Ciao!

 

[Big_John]

Here: Do yourself a BIG FAVOR and get a regulator from our own Mr. FuryGT:

Mopar Voltage Regulator - Electronic Solid State with Correct Restoration Look 724469250010 | eBay

He has a line on some GOOD solid state regulators from the Middle Socialist Republic!

Seriously, while I usually roast sino-products, these are the Exception. Get one, wire your alternator's second field lug to ground, rewire your charging harness with new stuff, over sized at least once, and you can kiss your problems Ciao!

He's bought the newer style isolated field regulator. Those are great but I think in this case, with adding some stereo equipment, going to this is a good move.

 

[Gerald Morris]

He's bought the newer style isolated field regulator. Those are great but I think in this case, with adding some stereo equipment, going to this is a good move.

I saw that. As you know, I run this 95 amp alternator w the same squareback hookup. Admittedly, the dual field regulator CAN be nice, and I'm mulling over getting one for mine, if circumstances warrant. Am looking this matter over carefully, as I like to tune the voltage to the ignition finely. Controlling the dual fields separately might avail for this.

But supplying plenty current for ones amps might be just as well served with a single field regulator, IFF its the RIGHT regulator! I get strong current for running my cooling fan thus. That's why I suggested FuryGT's wares if things don't work out for the OP with his current acquisition.....

 

[Big_John]

I saw that. As you know, I run this 95 amp alternator w the same squareback hookup. Admittedly, the dual field regulator CAN be nice, and I'm mulling over getting one for mine, if circumstances warrant. Am looking this matter over carefully, as I like to tune the voltage to the ignition finely. Controlling the dual fields separately might avail for this.

But supplying plenty current for ones amps might be just as well served with a single field regulator, IFF its the RIGHT regulator! I get strong current for running my cooling fan thus. That's why I suggested FuryGT's wares if things don't work out for the OP with his current acquisition.....

There's no such thing as a "dual field" alternator or regulator within this context. You either have an isolated field or an internally grounded field. The difference in alternators is really only the rear housing, truth be told.

Electrically, the difference is the later, isolated field alternator, is controlled by the negative side and the grounded field alternator is controlled on the positive side. I agree that in a lot of circumstances, the grounded field alternator with an works well, especially with the replacement electronic regulator. I run that in my '65 Barracuda and I believe the PO bought the electronic regulator from FuryGT.

In the OP's case, he's really going to be taxing the charging system and based on what I've seen and read, the isolated field type regulator may be the better way to go. Everything seems to point to the regulator being more robust and durable. If nothing else, the regulator now becomes a part store purchase with delivery within a day.

The windings on this Mopar rotor is the field. Not many seem to know this.

So much confusion on this...

 

[Gerald Morris]

There's no such thing as a "dual field" alternator or regulator within this context. You either have an isolated field or an internally grounded field. The difference in alternators is really only the rear housing, truth be told.

Electrically, the difference is the later, isolated field alternator, is controlled by the negative side and the grounded field alternator is controlled on the positive side. I agree that in a lot of circumstances, the grounded field alternator with an works well, especially with the replacement electronic regulator. I run that in my '65 Barracuda and I believe the PO bought the electronic regulator from FuryGT.

In the OP's case, he's really going to be taxing the charging system and based on what I've seen and read, the isolated field type regulator may be the better way to go. Everything seems to point to the regulator being more robust and durable. If nothing else, the regulator now becomes a part store purchase with delivery within a day.

The windings on this Mopar rotor is the field. Not many seem to know this.

So much confusion on this...

Yes, Mopar certainly liked to switch and control from the ground for some time, hence the "isolated" field.

One can tell that the rotor induces the field by virtue of the fact that the ferrous poles of the field are in it, thus sweeping the stator with a field, inducing 3 voltages spaced 120 degrees apart, just like the Big Boys do! Then the 6 or 12 rectifier diodes on the stator take these sinusoidal voltages, square them into the same polarity, add them together on the + output, and ground to the frame. The isolated field permits easier control over current and rotor voltage. There's a big power transistor in the regulator (or several, depending on when it was made and by who.) that opens its gate based on demand too. Definitely better at switching than mechanical points such as the old 1960s regulators used.

 

[Big_John]

Yes, Mopar certainly liked to switch and control from the ground for some time, hence the "isolated" field.

The best reason I ever heard was that the electronics didn't need as much insulation from the case, thus being cheaper to build.

There's probably more reasons....

But a lot of folks don't know that the alternator really puts out 3 phase AC that is changed to DC.