72 Swinger not charging battery

[scudzuki]

72 Dart Swinger project is still not charging the battery wheil running after a few attempted fixes. I reinstalled the Powermaster alternator that that came with the car after I bench tested it following directions I found on YouTube. 12V to the field connectors, spun it with a drill, 19V across the alt case and power stud. Another alt that came with the car only put out 15V tested the same way but that still passes AFAIK.
No charging when installed. Followed the same YT guy's directions for testing in the vehicle. Left the blue field wire connected to the field, connected the other field terminal from the alt to battery ground, started it, shot up to over 14V. Connected the green field wire to the alt, installed a new regulator, even added a ground from the reg case to another chassis ground point, but the battery is STILL draining while running (11.9-12V). Guess I can jumper the alt field terminals to the reg, rule out an issue with the wiring.

If any of you have some ideas I could try, I'm game.

Thanks.

 

[Dana67Dart]

You have done a good deal of the testing.

Sounds like the alternator is functional


The green wire provides a variable ground to regulate the output of the alternator.

The blue wire should have battery voltage when the engine is running


Testing the green wire ...

You can check voltage between the green wire and ground WHILE it is connected to the alternator and the engine is running. There should be a small voltage.

Also check

You can check voltage between the green wire and positive WHILE it is connected to the alternator and the engine is running. There should be a small voltage but larger then the other way around.

 

[scudzuki]

You have done a good deal of the testing.

Sounds like the alternator is functional


The green wire provides a variable ground to regulate the output of the alternator.

The blue wire should have battery voltage when the engine is running


Testing the green wire ...

You can check voltage between the green wire and ground WHILE it is connected to the alternator and the engine is running. There should be a small voltage.

Also check

You can check voltage between the green wire and positive WHILE it is connected to the alternator and the engine is running. There should be a small voltage but larger then the other way around.

And I have tested that, and there's a frction of a volt between the green wire (while connected to a field terminal) and ground, and around 9V between the blue wire connected to the other field terminal and ground with the key on not running. Still only 11.9-12V at 1000 RPM idle, unless I jump the green wire and terminal to battery ground, in which case voltage climbed to 14.9V before I shut the experiemnt down. Also tesed continuity betwwen the reg and alt ends of both the green and blue wire, a fraction of an Ohm resistance.

I'm stumped, unless the reg works UNTIL the engine is running THEN fails under normal load, everything seems to test out fine, as best I can tell given I'm a novice (at this, I'm fairly experienced otherwise).
Being as I can't buy a new reg that is not possibly a POS new out of the box, it's difficult to know where to go, unless I buy a pile of new regulators and keep testing until I find a good one. If that's the issue, which it almost has to be. But I see reports of new shitty regs dying after a month, too.

 

[Dana67Dart]

Your testing shows you regulator is functional as well.

What types of loads is the car running

 

[scudzuki]

Your testing shows you regulator is functional as well.

What types of loads is the car running

Tested as decribed in this video suggests it's the regulator.

The loads on the car are the HEI 1 wire distributor, MSD atomic throttle body EFI, and fuel pump, plus the relay that is triggered by IGN 1 and IGN 2 to provide battery power to the HEI MSD and fuel pump.
I could see the battery voltage being low at idle if the alt was not high output, but voltage remains at 12V max even if I rev the motor to 3000 RPM.
That is, unless I jump the green reg wire and alt field terminal to ground, in which case voltage climbs to at least 14.9V
I do have another alternator I can try.
Both alternators tested good on the bench using this method. Alt currently in car output 19V, spare alt output 15V

 

[67Dart273]

You MAY have an open in the charge wire AKA into the bulkhhead on the big black, through the ammeter circuit, back out the bulkhead on the big red, through the fuse link and to the battery

As Dana said, the IGN switch feeds +12 to one field terminal (does not matter which) and the VR effetively "controls the amount of ground" on the remaining field, (I think it is pulsed) which controls the field current and the output of the alternator

So to check the field circuit.....Unplug the VR and jumper the green wire connection to ground. Start it up, slowly bring up RPM and check voltage at the battery. IF IT does not come up, move your meter to the output stud on the alternator.

If this does not work, then it may be harness wiring. Go to the alternator, disconnect the green field wire and jumper that to ground, with the key in the "run" position. In reduced light you can usually see AND HEAR a small spark. With this connected, take your meter and confirm you have nearly battery voltage at the blue field terminal. DO NOT disconnect the wire, check this by "backprobing" the terminal. If you cannot reach them, switch the connections around, AKA move the blue to the opposite field terminal and ground the remaining one.

If this checks out, try again, run the thing as it sits connected, and recheck battery and alternator output stud. If this works, check the green wire for continuity.

The VR MUST BE GROUNDED. "Work" the VR connector in/out several times to "scrub" the terminals, and feel for tightness, and inspect the female and male terminals closely with a pocket light.

This is a simple circuit. The key feeds "ignition run" to the blue VR terminal, the ignition system, and the blue field wire. The VR controls "grounding" on the remaining field

The black output wire goes through the bulkhead, through the ammeter, back out on the "big red" and to the battery.

 

[scudzuki]

You MAY have an open in the charge wire AKA into the bulkhhead on the big black, through the ammeter circuit, back out the bulkhead on the big red, through the fuse link and to the battery

As Dana said, the IGN switch feeds +12 to one field terminal (does not matter which) and the VR effetively "controls the amount of ground" on the remaining field, (I think it is pulsed) which controls the field current and the output of the alternator

So to check the field circuit.....Unplug the VR and jumper the green wire connection to ground. Start it up, slowly bring up RPM and check voltage at the battery. IF IT does not come up, move your meter to the output stud on the alternator.

If this does not work, then it may be harness wiring. Go to the alternator, disconnect the green field wire and jumper that to ground, with the key in the "run" position. In reduced light you can usually see AND HEAR a small spark. With this connected, take your meter and confirm you have nearly battery voltage at the blue field terminal. DO NOT disconnect the wire, check this by "backprobing" the terminal. If you cannot reach them, switch the connections around, AKA move the blue to the opposite field terminal and ground the remaining one.

If this checks out, try again, run the thing as it sits connected, and recheck battery and alternator output stud. If this works, check the green wire for continuity.

The VR MUST BE GROUNDED. "Work" the VR connector in/out several times to "scrub" the terminals, and feel for tightness, and inspect the female and male terminals closely with a pocket light.

This is a simple circuit. The key feeds "ignition run" to the blue VR terminal, the ignition system, and the blue field wire. The VR controls "grounding" on the remaining field

The black output wire goes through the bulkhead, through the ammeter, back out on the "big red" and to the battery.

I've done all these things already, as I've already described in the thread.
The alt charges the batt as soon as I jump the field terminal with the green wire to ground.
Fusible link is good, wire to ammeter is not an issue, otherwise batt voltage would not increase with the green teminal jumped to ground.
Thanks for the help.

 

[Dartswinger70]

Bad battery?

 

[scudzuki]

Bad battery?

No. Load tested battery, it's pretty good. 12.6V fully charged.

 

[Dartswinger70]

Voltage regulator? is it internal or external? if its original older mopar its on the firewall...

 

[scudzuki]

Voltage regulator? is it internal or external? if its original older mopar its on the firewall...

I thought I included this detail but maybe not.

I bought a new VR, and added a ground strap to its chassis from a common ground.

Issue exists with the original VR and the new one, but as I understand it, new VRs are generally crap, so there's no guarantee that the new one works.

I'm gonna buy one of the adjustable ones sold by MadScientistMat once they're available.

I'll **** around with it some more this afternoon.

 

[Dartswinger70]

Its a tough call and I will say that I once used a troubleshooting guide to troubleshoot the ignition system on a Dodge truck I think it was a 77 Dodge. The tests came back that the module was good but no spark. I then decided "it has to be the module" tossed one in and it started right up...you may be right that your supposed good regulator isn't good. the thing is youll spend time shooting wires etc when it is a part.

 

[scudzuki]

Its a tough call and I will say that I once used a troubleshooting guide to troubleshoot the ignition system on a Dodge truck I think it was a 77 Dodge. The tests came back that the module was good but no spark. I then decided "it has to be the module" tossed one in and it started right up...you may be right that your supposed good regulator isn't good. the thing is youll spend time shooting wires etc when it is a part.

Yeah it's not a rational pursuit, this classic car hobby. LOL.

 

[67Dart273]

Don't discount that it might simply be the CONNECTOR at the VR

 

[scudzuki]

Don't discount that it might simply be the CONNECTOR at the VR

I already plugged and unplugged it several times to wipe the connections BUT I can squeeze the female connectors to tighten them.
BTW, I did the key-on test from the alt field terminals to ground and found the terminal with the green wire connected had around 1V and the one with blue wire connected had 8V which I don't believe would be the case if the connection to the VR was bad.

 

[67Dart273]

8V? What does it measure running? that could be the problem, very low voltage, may not be enough to "key" the VR into operation. I've no idea what that threshold might be.

 

[Dana67Dart]

BTW, I did the key-on test from the alt field terminals to ground and found the terminal with the green wire connected had around 1V and the one with blue wire connected had 8V

I'm assuming you are testing the 12v feed to the VR.

It should be battery voltage as that's the same wire the VR reads to determine how much load the alt needs to cover

As 67dsrt273 stated that might not be enough to cause the VR to work.

You can use clip leads from battery plus to the proper post on the VR and another clip lead from the field terminal on the alternator that the green wire was on to the post on the VR that the green wire goes to.

If it starts charging trace out the blue wire. It sounds like it's coming from the coil side of the ballast. It should be coming from the ignition side of the ballast.

 

[scudzuki]

8V? What does it measure running? that could be the problem, very low voltage, may not be enough to "key" the VR into operation. I've no idea what that threshold might be.

That's what it's supposed to measure, less than 12V. That's supplied by the VR. With the key off both fields terminals (with their respective VR wires connected) measure in the mv range. I'll get out there tomorrow before it hits 100 degrees working in my driveway. Got a different alt to swap in.

 

[Dana67Dart]

That's what it's supposed to measure, less than 12V. That's supplied by the VR. With the key off both fields terminals (with their respective VR wires connected) measure in the mv range

The blue wire is supposed to be battery voltage to the VR and to the alternator. So if you measure the blue wire anywhere along it's path it should be battery voltage, at the VR or at the field terminal on the alternator.

The green wire will have varing voltages on it as the VR determines how much voltage the alt needs to supply.

Note the pin locations are just for example on the VR.
(I goofed on the line from the ballast to the coil. It will be less than battery voltage)

In a grounded field alternator one field terminal is grounded and the other coming from the VR varies from about 6 to 10 v.

 

[67Dart273]

That's what it's supposed to measure, less than 12V. That's supplied by the VR. With the key off both fields terminals (with their respective VR wires connected) measure in the mv range. I'll get out there tomorrow before it hits 100 degrees working in my driveway. Got a different alt to swap in.

You have a problem, and you haven't read my earlier post. The BLUE field wire is switched 12V from the key "run" circuit. It is NOT supplied by the VR. This run circuit, often dark blue, comes through the bulkhead, and depending on year, feeds power to the ignition system (high side of the ballast), power to the VR (ign terminal, blue) and the blue wire to one field. THAT SHOULD BE very close to "same as battery."

The VR green, which I believe is pulsed, controls the "amount of ground" on the green field. This completes the field circuit and is the control method. With all wires connected normally, and key in "run" the blue field wire, still connected, should read close to battery V

 

[scudzuki]

You have a problem, and you haven't read my earlier post. The BLUE field wire is switched 12V from the key "run" circuit. It is NOT supplied by the VR. This run circuit, often dark blue, comes through the bulkhead, and depending on year, feeds power to the ignition system (high side of the ballast), power to the VR (ign terminal, blue) and the blue wire to one field. THAT SHOULD BE very close to "same as battery."

The VR green, which I believe is pulsed, controls the "amount of ground" on the green field. This completes the field circuit and is the control method. With all wires connected normally, and key in "run" the blue field wire, still connected, should read close to battery V

The blue wire goes to the VR. It is switched 12V so it is not directly from the battery. It is not full battery voltage due to resistance in the wiring. I did read your full post. I may be wrong about the 8V, it could be higher than that, but it was not the same as the battery voltage, I'm sure of that. If it's lower than the actual battery voltage, the field would be excited more by the VR, so with a working VR, the charging voltage should be even higher. I've been on and off this thing between working my real job. Thanks for your contribution and enjoy your 4th

 

[Dana67Dart]

. If it's lower than the actual battery voltage, the field would be excited more by the VR, so with a working VR, the charging voltage should be even higher

Agreed, IF it has enough voltage to power on and work. You will need to retest a few things to determine if your switched battery voltage has that big of a drop.

A 4 volt drop is a lot and a car battery almost never gets that low.

 

[scudzuki]

The blue wire goes to the VR. It is switched 12V so it is not directly from the battery. It is not full battery voltage due to resistance in the wiring. I did read your full post. I may be wrong about the 8V, it could be higher than that, but it was not the same as the battery voltage, I'm sure of that. If it's lower than the actual battery voltage, the field would be excited more by the VR, so with a working VR, the charging voltage should be even higher. I've been on and off this thing between working my real job. Thanks for your contribution and enjoy your 4th

Not a functioning battery anyway. Switch voltage to the coil was less than 12V when I installed the HEI distributor which is why I installed a relay and use the coil wire to trigger that relay.
Measured just now with key on
batt 12.28V
blue field wire 10.08V
green 399 mV

is 10V enough to trigger the reg to ground the green field wire?
Should I splice switched 12V from the relay I installed to the reg and alt blue so it's getting 12.3V?

Thanks

 

[67Dart273]

The blue wire goes to the VR. It is switched 12V so it is not directly from the battery. It is not full battery voltage due to resistance in the wiring. I did read your full post. I may be wrong about the 8V, it could be higher than that, but it was not the same as the battery voltage, I'm sure of that. If it's lower than the actual battery voltage, the field would be excited more by the VR, so with a working VR, the charging voltage should be even higher. I've been on and off this thing between working my real job. Thanks for your contribution and enjoy your 4th

You still have it wrong. First I never said the blue came from the battery. I actually SAID it was switched 12V. I know ALL ABOUT harness drop, and all I can do is go by what you said, which is 8V

THE VR DOES NOT EXCITE THE FIELD. It merely controls the field current from the source, AKA the blue from the switch.

WHAT CAUSES OVER VOLTAGE from the VR circuit is the voltage drop in the blue "run" circuit as seen AT THE VR. That is because the voltage drop makes the VR "think" that voltage is low, so it ramps up field current. This problem is NOT caused by the field circuit. It is caused completely by voltage drop in the ammeter, the bulkhead, and the "ignition run" feed circuit, and culminates AT THE VR ign/ power terminal

One way to address this drop is to cut the blue ign "run" lead coming out of the bulkhead, electrically. Run the bulkhead end to trigger a relay, and connect the engine bay end to the switched contact. Feed the power contact from say, the start relay with no12 and a fuse or breaker.

 

[scudzuki]

You still have it wrong. First I never said the blue came from the battery. I actually SAID it was switched 12V. I know ALL ABOUT harness drop, and all I can do is go by what you said, which is 8V

THE VR DOES NOT EXCITE THE FIELD. It merely controls the field current from the source, AKA the blue from the switch.

WHAT CAUSES OVER VOLTAGE from the VR circuit is the voltage drop in the blue "run" circuit as seen AT THE VR. That is because the voltage drop makes the VR "think" that voltage is low, so it ramps up field current. This problem is NOT caused by the field circuit. It is caused completely by voltage drop in the ammeter, the bulkhead, and the "ignition run" feed circuit, and culminates AT THE VR ign/ power terminal

One way to address this drop is to cut the blue ign "run" lead coming out of the bulkhead, electrically. Run the bulkhead end to trigger a relay, and connect the engine bay end to the switched contact. Feed the power contact from say, the start relay with no12 and a fuse or breaker.

IGN 1 puts out well below battery voltage which is why all it does for the ignition EFI and fuel is trigger a relay, as you described above.
This was the first thing I did weeks ago as I suspected the voltage from IGN 1 may not run an HEI distributor.
I needed a relay anyway for the EFI and fuel pump.
I looked earlier at what I did when I wired in the relay and realized the 2nd blue wire on the trigger side of the relay IS the VR/alt blue.

I also understand how the VR works. Perhaps excite was the wrong term. The VR controls the strength of the field based on batt V by manipulating the ground on the green wire.

When I just jumped battery + to the blue field wire bat voltage jumped to 13.7V

I'll separate the blues at the firewall, continue to trigger the relay with IGN 1 from the key, and drive the alt/reg blue from the output side of the relay so it's batt V AND switched.

Thanks.

Edit; the harness on this beast is even worse than I thought. I can't find where the blue to the alt is connected to IGN 1. The VR blue was the other wire I HOPED was connected to the alt blue. Peeled off layers of electrical tape and found splices all over the place, splices to different colred wires that go God knows where... Maybe I will spring for one of those HUGE color laminated wiring diagrams.

Also something I forgot to mention is the ammeter in the dash indicates the battery is charging. I don't know how that could be because I tested the V out of the battery terminal on the alt and it shows the same as battery V. Doesn't the alt batt terminal go through the ammeter?