Anyone know of a source for an “electronic” voltage regulator that puts out no more than 14.2-14.4 volts?

[72RoadrunnerGTX]

1970? Assuming an original charging system, it should have a dual isolated field alternator (two field wires, green and blue). No field brushes or terminals should be grounded if running the original style 1970 and up electronic VR.

 

[Woodwiz]

It is a 70 RR w/383,this alternator was in it when purchased and it is a round back as they say. The one field location is grounded to the case and more accessible other field connection has what appears to be a grayish wire attached and the there’s the power lead running back to where it ties into wires that go to the VR & ballast resistor. That’s what I see. I’m heading out to run your suggestion to test the alternator,l’ll let you know soon.

 

[72RoadrunnerGTX]

It is a 70 RR w/383,this alternator was in it when purchased and it is a round back as they say. The one field location is grounded to the case and more accessible other field connection has what appears to be a grayish wire attached and the there’s the power lead running back to where it ties into wires that go to the VR & ballast resistor. That’s what I see. I’m heading out to run your suggestion to test the alternator,l’ll let you know soon.

If you are only seeing one field wire and are running the correct VR and alternator for the car then you have a wiring problem. You will need to verify you have the correct dual isolated field alternator for use with the factory electronic VR and that the connections are correct, no field terminals should be grounded.

 

[Woodwiz]

OK! Just got done with the test you suggested and here's what i got:
1.VR unplugged start engine and voltage on gauge and meter=17.2v
2. The only field wire disconnected w/VR unplugged=12.7v
3. Field wire unplugged w/VR plugged back in=12.7v
This alternator was with the car when purchased single pulley.
Does any of this info help with your figuring out what this all means?
A buddy of mine that runs a hot rod shop was thinking maybe replacing the old engine harness.
but like you said i don't want to just throw parts at it on a hope it works.

 

[Woodwiz]

Also for what it's worth,the VR that was on it when i got it,my guys at the shop installed the electronic ignition in the distributor and a high output coil.

 

[72RoadrunnerGTX]

OK! Just got done with the test you suggested and here's what i got:
1.VR unplugged start engine and voltage on gauge and meter=17.2v
2. The only field wire disconnected w/VR unplugged=12.7v
3. Field wire unplugged w/VR plugged back in=12.7v
This alternator was with the car when purchased single pulley.
Does any of this info help with your figuring out what this all means?
A buddy of mine that runs a hot rod shop was thinking maybe replacing the old engine harness.
but like you said i don't want to just throw parts at it on a hope it works.

This verifies the issue is a wiring problem between VR and the alternator field circuit, alternator is being full fielded, and the VR has no control of the field current. Next step I would do is verify you have the correct parts. First the alternator, you do have two field terminals? Remove any connectors from both of them, check that there is no continuity to ground from either terminal with a VOM. The VR? You are working with the correct ’70 and up electronic VR? If the parts are correct, one of your field wires is missing, see the above diagram. Sounds like it’s the green field run from the VR to the alternator is missing.

 

[Woodwiz]

From all I can tell the alternator is period correct . The service manual shows a spot on identical one in the book. There are 2 connections 1-field/1-black wire to the VR.
That’s it per the book.
In the area near the wires are a couple separate green wires with slide on connectors that have never been attached to anything…don’t know if it matters.
Gotta ask is there a way to run a heavy gauge wire from the alternator post to the ground of the battery or VR ground or to the starter relay or am I just grasping at straws??

 

[72RoadrunnerGTX]

What book is it you have showing two wires only at the alternator for 1970? If you do have a 1970 FSM, it is pretty clear on the details of how this system is wired and functions. The black 12ga wire is the alternator output, the blue 18ga field wire is ign1, the green 18ga field wire runs straight to the regulator. There should be three wires total, none are to be grounded. Maybe post some pictures of your extra wires near the alternator.
This is from the 1970 Chrysler/Plymouth FSM.

 

[dadsbee]

The one field location is grounded to the case and more accessible other field connection has what appears to be a grayish wire attached and the there’s the power lead running back to where it ties into wires that go to the VR & ballast resistor.

There's the problem RIGHT there! Correct 70's wiring, blue wire to VR and Ballast. Now you've got the dual field alternator grounded on one side and feeding it battery voltage on the other field and I assume using a 69 and earlier voltage regulator. I assume because of zero pictures or statements. Even though you've pulled the lead off the VR, it's still tapped into the battery feed via the blue wire and full fields the alternator.

The easiest forum on the internet to upload pictures, that speak a thousand words on your behalf...

Your alternator is definitely GOOD.

 

[Woodwiz]

Just had an epiphany of sorts checking out the wiring diagram. This may look like a factory alt. But just not for this car. That being said the wire to the only attachment for the field is a faded blue and I also have 2 separate green wires that have never been attached to anything much less the alt.
My guess is this car needs the right alt. with 2-field and 1-output. It could have been slapped on who knows when and not spec’d for this year system.
Any opinions? Oh here’s some pics!

 

[bobsgtx]

You could save some money if you can get a brush insulator kit to insulate the grounded brush and hook the wire from the regulator to it.

 

[72RoadrunnerGTX]

Just had an epiphany of sorts checking out the wiring diagram. This may look like a factory alt. But just not for this car. That being said the wire to the only attachment for the field is a faded blue and I also have 2 separate green wires that have never been attached to anything much less the alt.
My guess is this car needs the right alt. with 2-field and 1-output. It could have been slapped on who knows when and not spec’d for this year system.
Any opinions? Oh here’s some pics!

The alternator casting is specific to the round back dual insulated field alternator, needs to support the use of the insulated brushes. Pull the alt off and post some better pics of the back of the alt and field terminals. As mentioned, it’s looking like you are running an alt for a ’69 and back, for a mechanical VR. Possible too, could be the correct alt with one brush intentionally grounded for use on an up to '69 application. One of those extra green wires is likely for dual horns. Being a single horn Road Runner, there will an extra horn lead hanging around there, should have a red trace on the green horn wire.

 

[Woodwiz]

Here’s the deal. I have more than one green wire in the area and if indeed someone put a 69 specific alt.on which it’s starting to feel that way. The ones for 70 are 2 field 1bat.

 

[Woodwiz]

I found a great video on the Tube. It is a Chrysler co.vid from the old days. A lot of stills and two well dressed techs talking about the different alternator/VR’s of the day.
I have determined that I currently have an alt.from 1969,but I have wiring for a 1970…solution? Get a 2field for a 70 and with extra couple of wires from the bunch coming to the alt.give it a try. I can always return the alt. to Napa if I can’t resolve this issue. But I’m feeling good about it.
Another thing my alt.repair guys said might be is the high voltage passing through the VR could have fried it, but I guess we shall see.

 

[72RoadrunnerGTX]

This Volume 70-4 Master Tech side show from the day? yes, if you only have one field terminal, it's the wrong alternator for the application. I'd be a little worried about over-voltage and the Dakota Digital dash myself. On the replacement, be sure to verify there is no continuity to the case from either field terminals before making any connections. Rebuilt versions of these alts have reputation of missing insulators and shorted brushes.

 

[Woodwiz]

When I put the digital dash in and drove it around to calibrate the speedo,not knowing what I know now I’m pretty sure there was the high voltage running through everything. No excuse for not checking continuity. The dash is all low volt LED. What is your worry about putting the electrical back as intended?

 

[72RoadrunnerGTX]

No concern with the DD and a normal charging system voltage range, only with the current over-voltage situation.

 

[Woodwiz]

I got lucky with my digital dash as it was running high volts through it and I was not aware.
Thanks for all the help everyone

 

[Woodwiz]

What kind number am I looking for on the meter for continuity?

 

[72RoadrunnerGTX]

On a digital VOM? 0.00 shows continuity, you don’t want continuity from either field terminal to the case. Should not be any reaction or reading with a digital VOM. Touch the probes together, what ever reading you see, you don’t want that between the terminals and the case.