one wire Alternator and voltage regulator question

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like_A_pike

like_A_pike

that's not factory
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Please help me understand how this works. The replacement alternator I got has the square back and the directions say to not use my voltage regulator (VR). Does the regulator do anything other than protect the battery from overcharging? How does the one wire or "squareback" alternator do that?

I still have the VR hooked up. The car seems to run ok but am I over regulating, loosing power, or stressing my coil unnecessarily? Should I just delete it?

thanks in advance

D
 
Need WAAAAAY more info.

There are many types of alternators

  1. Single field wire round back
  2. Double field wire round back
  3. Single field wire square back(actually a double field wire with one of the field wires grounded)
  4. Double field wire square back
There are also other alternators which are refered to a single wire (GM) that only have the one wire to the battery, no field wires.

So from what you have stated I have no idea what alternator you have and have no idea what alternator you should have AND have no idea what regulator you have.

  1. What year is your car
  2. What modle is your car
  3. What engine is in your car
  4. What modifications have been done to the electrical system
  5. Post photos of the current alternator
  6. Post photos of your old alternator
  7. Post photos of your regulator
  8. Measure the voltage at the battery with the engine off
  9. Measure voltage at the battery with the engine on
 
I don't know what alternator I had in it. It was one of those chromed "powermasters" but had the round style body and it had the field wire connected back to the VR when I bought the car. At that point there was a Petronix distributor but I swapped it out to the orange box and electronic Mopar Perfomance deal back in 2012. I left the VR in. About 2018 that alternator died. I had a local guy rebuild it but I think he left the spacer out of the middle and it ate itself up inside. (is that possible) anyway I bought this a new chrome powermaster with the squareback and the aforementioned guidance on the field wire delete. (which i have ignored) Let see its a 68 barracuda just like the one in my avatar with a 1971 340 and currently hooked up to a chrome box and an Accell coil. battery off it's at 12.54.
DSC_0206.JPG

I have two VR mounted. (I had been alternating between them). I usually ran the blue one.
my ammeter always read 14 with my old set up and my fusible link wire was always HOT. After fixing some resistance points and the addition of a new alternator, that ammeter barely settles much above 12. (same gauge)
I'll work on the rest of the questions and read up on Mattax attached link in the morning.
 
Thanks for the info but we still need a photo of the alternator.

The black alternator is typical pre 68 or 69 mechanical 1 field wire voltage regulator.

Can't see the blue regulator to see what it is.
 
like_A_pike said:
my ammeter always read 14 with my old set up and my fusible link wire was always HOT. After fixing some resistance points and the addition of a new alternator, that ammeter barely settles much above 12. (same gauge)
Click to expand...
Not sure what you are reading as an ammeter.

A ammeter reads amps and the one built into the dash should be streight up to slightly to the right when the engine is running. If you turn on the head lights and apply the brakes at idle the indicator might go slightly to the left of center.

If you are doing as I asked, you are using an external volt meter to measure voltage between the positive and negitive posts on the battery.
 
HERE IS THE THING. In addition to what the guys have tried to tell you, AFTERMARKET people such as powermaster do indeed make/ sell a "modified" version of Chrysler alternators WITH A REGULATOR on/ or in the alternator. IF you have this type, then you do NOT connect an external regulator.

You still have not shown or told us WHAT EXACTLY you have for an alternator. We need a link or part number or photo that shows the rear of the alternator

WHAT IS difference between regulators/ and one wire:

1....Up through 69, "stock" Mopar alternators had ONE field connection, having the remaining field brush grounded. The regulator was made for this of course

2....In 70 and later, the field magnet was ISOLATED (insulated) and the second brush was brought out to a terminal just like the first, so now TWO field connections. The 70/ later regulator is quite flat

3....Integral regulator. Delco made these popular in GM cars. The regulator in the mid 70's began to be built INTO the alternator. The regulator STILL HAD two external connections, one for "voltage sense" and one for the idiot light/ "exiter" connection

4...Then some genius MODIFIED the Delco style regulator so that it was "self excited" and now it DID NOT NEED any outside connections except the main output wire, hence "one wire"

5...Nowadays, there are many/ several 3rd party/ aftermarket outfits that sell various modified alternators WITH AN INTERNAL regulator WHICH IS "self exciting" and therefor is a "one wire" setup
 
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looks like there is a Blue 69 down regulator on the fire wall as well. Way more better pics needed!
 
REGULATOR

A regulator does WAY WAY more than just simply "prevent overcharge." It does exactly what the name says "it regulates voltage."

Automotive systems ARE NOT 12V!!!! That is correct!!!!!

A properly operating charging system when running, operates at a target max, when battery is down/ under full load, or almost no load, or extreme cold or extreme hot, somewhere in the range 13.5--15V

A warm, happy, "normalized battery" under optimum conditions operates between 13.8 and 14.2V that is, "nominal" 14V operating voltage
 
How do folks get in this mess!

lots of pics and numbers needed to steer to the right direction!
 
looks like the blue\white is tied to the field on the 69 down electronic regulator! This is a small mess!
 
POWERMASTER. Their website is a POS!!!

IF IF you have a Powermaster "one wire" it should look something like this, it should have a wire "magically" coming out the back which is connected to one of the field connections

IF THAT is what you have, you do NOT connect ANY OTHER WIRES to that alternator EXCEPT the large (originally black) charge / output wire, IE the "battery post 1/4-20" near top of photo

powermaster.jpg
 
67Dart273 said:
POWERMASTER. Their website is a POS!!!

IF IF you have a Powermaster "one wire" it should look something like this, it should have a wire "magically" coming out the back which is connected to one of the field connections

IF THAT is what you have, you do NOT connect ANY OTHER WIRES to that alternator EXCEPT the large (originally black) charge / output wire, IE the "battery post 1/4-20" near top of photo

View attachment 1715698612
Click to expand...

Yes, this is the one I have (note the part No. has changed a little) If you go to Mopar and click the link "094" under instruction sheet, It seems to suggest connecting the one field wire. However the instruction sheet that came with the alternator says not to connect it.
DSC_0208.JPG
DSC_0210.JPG


so you can see what looks like my old green field wire that goes to the VR.

DSC_0207.JPG

I will test the voltage while the car is running and report back a little later. I'll do the suggested 1500 rpm pull on that "094" sheet and use a multimeter. I'll post the output with each VR and then no VR. I mentioned an ammeter earlier referencing an aftermarket gauge in the dash.
 
No idea what your instruction sheet says or looks like.
Only this, which indicates this model is an isolated field alternator.
http://www.powermastermotorsports.com/094__Chrysler_Alternators.pdf

Powermaster 75191 Powermaster Retro Alternators | Summit Racing

If this is what you have then you need to set up as shown in the thread about identifying chrysler alternators. There's a post there about using an isolated field alternator in place of a grounded field alternator.

Either of those regulators in your car will work - assuming they are not damaged.

The photos show the 75191 is a revised squareback. If thats what you have, those regulators may have trouble handling the field current.


battery off voltage of 12.54 V is a bit low. I'd put it on a charger.
like_A_pike said:
I mentioned an ammeter earlier referencing an aftermarket gauge in the dash.
Click to expand...
Still don't understand this.
Aftermarket or factory, an automotive ammeter shows current flowing in or out of the battery. Current is measured in amperes.
A voltmeter shows energy level between two locations. As a dash gage or underdash gage, one is ground and the other is someplace on the run or accessory circuits.
 
I do not think that instruction sheet is either complete or correct. At no point do they address "one wire" specifically.

Also INcorrect is the voltage check. They mention that "if voltage is above so much" alternator is defective. THIS IS OFTEN NOT THE CASE because of external voltage drop problems in the case of a non- one wire setup and is in fact rarely the case. Whoever wrote that mess needs to re-nig
 
upload_2021-2-28_12-7-14.png


not the greatest or totally controlled experiment and I added some tests on the (+) side of the coil.
Yeah Mattax, the battery lost some ground after our crummy weather spell last week and did require some charging to get it to 12.5. It got up to 12.7 after running for 15 minutes or so this morning. I think that I am using the word ammeter and the gauge in the dash as the same thing erroneously. thanks for that...
 
Although the ammeter is absent we can assume with 13.8 V at the battery positive, its getting recharged slowly.

If you take a voltage reading at the alternator output terminal (stud) and compare with the battery reading, you'll know if there is a resistance to flow between the alternator and the battery. Also look what the dash voltmeter is reading since its probably tapped into a keyed circuit. In theory they should all be the same. In reality current flowing through wires and connections encounters resistance. The result is loss of energy -> that is, voltage drop.

Side note:
Ignition voltages on the coil side of the resistor all make sense.
The reason its 9.4 to 10.9 volts when starting is because starter is sucking a lot of energy from the battery during start.
If you measure the battery voltage during start you'll see the voltage drops significantly.
 
like_A_pike said:
View attachment 1715698911

not the greatest or totally controlled experiment and I added some tests on the (+) side of the coil.
Yeah Mattax, the battery lost some ground after our crummy weather spell last week and did require some charging to get it to 12.5. It got up to 12.7 after running for 15 minutes or so this morning. I think that I am using the word ammeter and the gauge in the dash as the same thing erroneously. thanks for that...
Click to expand...
The readings in the left column tell the story. Does it ever go above 14-14.5 max? if not "you are good." It surely is a "one wire."

NOW what do you have for a charging path to the battery? You do NOT want to depend on factory wiring for a "one wire" it needs to be up--gauged. Plus if the old ammeter wiring is in place (bulkhead connector) that can be a big problem
 
67Dart273 said:
The readings in the left column tell the story. Does it ever go above 14-14.5 max? if not "you are good." It surely is a "one wire."

NOW what do you have for a charging path to the battery? You do NOT want to depend on factory wiring for a "one wire" it needs to be up--gauged. Plus if the old ammeter wiring is in place (bulkhead connector) that can be a big problem
Click to expand...
I haven't seen 14 since the alternator swap so i think it's ok. I'd hate to admit to YOU what's going on with the charging path. Some of the path has been replaced with larger wire and a 30 amp fuse. Anyway I'll endeavor to upgrade the rest of it sooner than later.
thanks for taking the time....
 
A parallel path helps, because it relieves pressure on the original, the bulkhead. 30A may not be enough tho

IF EG you create a short parallel charging path direct to the battery, this drops the original problem by more than half, even if you only use the same size wire. This is because battery charging current is now greatly reduced through and back out of the bulkhead, and that current is mostly "INTO" the car for headlights, etc. The fact that the new path is shorter and does not have lossey terminals/ connectors means a much lower resistance path
 
Mattax said:
If you take a voltage reading at the alternator output terminal (stud) and compare with the battery reading, you'll know if there is a resistance to flow between the alternator and the battery. Also look what the dash voltmeter is reading since its probably tapped into a keyed circuit. In theory they should all be the same. In reality current flowing through wires and connections encounters resistance. The result is loss of energy -> that is, voltage drop.
.
Click to expand...

I took the opportunity to up gauge the wiring from the alternator to the bulkhead.
I had larger gauge wire on the other side but under the hood it was still original I think; black wire wrapped with the green field wire and even the violet sending unit dead headed in there too. I deleted the voltage regulator altogether and now my multimeter spikes to 14.8v (generally 14.3) at the alternator stud and the battery at idle (~800). the voltmeter on the dash never reads higher than 13.8ish volts. I replaced my battery today too as it wasn't holding a charge anymore. The new battery was reading 12.45 when I first put it in btw.

67Dart273 said:
The readings in the left column tell the story. Does it ever go above 14-14.5 max? if not "you are good." It surely is a "one wire."
Click to expand...

I will put the VR back tomorrow and see if I can stay below 14v.

thanks again
 
Are you sure you don't have a parasitic drain on the battery?
 
no sir, not 100% sure. Although that battery was around 5 years old and it sat for most of 2020 while the engine got long blocked. The cold snap we had last month seemed like the coup de grace.
On the other hand this is the first time I've had the wire harness out of the electric tape (mine since 4/11) I am up to 6 dead end wires and 2 had some charge to them when the key was on. Most of them seem to be sending unit wires for old instruments and I've been eliminating them as I go.
 
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