Alternator Question (not charging the battery):

[MaximRecoil]

Hi there Pete,

Thank you for taking the time to check out the pics that I had sent. For the multimeter, I looked for an upside down 'U' - the only thing that I had seen that was close was the battery cable symbol and the numbers ending in the letter 'K.' I put it on the 200K setting, which read:

1.) Touching the two leads together: 00.0 (then, I went over to disconnect the negative battery cable),
2.)  Disconnected the green wire at the alternator terminal. Put one lead onto that alternator terminal and one to the casing of the alternator for a ground: it read: 00.0.
3.) I then repeated the same steps with the second terminal where the new red wire was intended to go, and, it too was: 00.0.
4.) I then put one lead on one terminal and the other lead on the second terminal across each other. Again, 00.0.
5.) I then had the green wire re-installed on the regular point and found a ground just to see if anything different would show by chance, and it was 00.0.

So, in a nutshell, everything was 00.0 all around. If you guys need me to do any more tests/readings, please let me know and what you may think based on these numbers. Based on this info; it looks like I may have to make a ground/jumper wire to run off of the second field terminal (where they had the red wire intended to go) onto a dead bolt...

Best regards,
Aaron

I don't know what to make of those readings. Maybe someone else will, but some meters have different ways of doing things. What you're trying to do is a continuity check, and if there is no continuity there will be no reading at all, no different than if your meter's probes weren't touching anything. If there is continuity then the meter will do something. If you have it set to measure resistance (ohms), you will get a low value if you have good continuity, such as if you touched both probes to a penny. There is really no such thing as 0 ohms under normal conditions, as your readings would suggest, because outside the realm of superconductivity, everything has some resistance, even if it is minuscule.

Does your meter have a continuity check mode? Look for a symbol like an arrow combined with a cross, like this - link. It may "beep" when you have continuity, or it may not, depending on what meter you have. Either way, it will do something if you have continuity, whereas it will do nothing if you don't have continuity.

I suggest trying your meter in continuity mode (the resistance check as suggested by previous posters accomplishes the same thing, but if you were on 200K [200,000 ohms] that's way too high a setting for a continuity check; you should be on 200 ohms) with something that you know has continuity just so you can see what your meter does when there is continuity.

Set your meter to the setting which has the arrow/cross symbol (it may have a sound wave looking symbol too, which means it can beep when there is continuity), and touch the probes together (or touch them both to the alternator case, or whatever), and take note of what your meter does.

When you're testing your field terminals on your alternator, what you're trying to determine is if either one of them is grounded, that is, if either one of them can conduct electricity to ground, which ultimately leads back to your negative battery terminal. The metal housing of your alternator is grounded by default, because it is bolted to your engine block, which has cables connected to it which ultimately lead back to your negative battery post.

Once you know what your meter does when you have continuity, do the test on your alternator again; i.e., hold one probe to the alternator case and the other probe to one of the field terminals, and then do the other terminal. If you get a reading, that means that terminal is grounded. If you don't get a reading (i.e., the same as if your probes were touching nothing at all), it is not grounded. Also, make sure the probes are getting good electrical contact when you do the test; sometimes this means scraping or sanding to reveal some clean bare metal, if you are testing on dirty or oxidized surfaces.

[Captain D]

Hi there Maxim,

I did find the symbol on my multimeter that you had noted in your link. Simply repeating the same process, things read as (with the negative battery terminal still disconnected):

- I touched both wire leads of the multimeter together and they registered at 002.
- Disconnected the green wire at the alternator terminal. Put one lead onto that alternator terminal and one to the casing of the alternator for a ground: 002.
- I then repeated the same steps with the second terminal where the new red wire was intended to go, and, it was: from 006 to 007.
- And, I then put one lead on one terminal and the other lead on the second terminal across each other: 007.
- I then had the green wire re-installed at the regulator point and found a nearby ground just to see if anything different would show. It registered at: 025.

Although its not crucial, if mine does require a ground for the alternator its odd that this particular part # didn't have the necessary stud/post already provided to begin with. I hope that these numbers helped any, and again, if you need any more info - just let me know,
Aaron

[MaximRecoil]

Hi there Maxim,

I did find the symbol on my multimeter that you had noted in your link. Simply repeating the same process, things read as (with the negative battery terminal still disconnected):

- I touched both wire leads of the multimeter together and they registered at 002.
- Disconnected the green wire at the alternator terminal. Put one lead onto that alternator terminal and one to the casing of the alternator for a ground: 002.
- I then repeated the same steps with the second terminal where the new red wire was intended to go, and, it was: from 006 to 007.
- And, I then put one lead on one terminal and the other lead on the second terminal across each other: 007.
- I then had the green wire re-installed at the regulator point and found a nearby ground just to see if anything different would show. It registered at: 025.

So both field terminals are grounded? "002" indicates good continuity, just as good of continuity on your meter as when touching the two probes together. "006" or "007" is still continuity. Maybe something isn't right with your alternator.  

I'll let Pete in NH advise you on how to proceed from here (if it were me, I'd return the alternator and regulator, then ask for an alternator and regulator for a '70s Mopar, mount and wire them up and be done).

Although its not crucial, if mine does require a ground for the alternator its odd that this particular part # didn't have the necessary stud/post already provided to begin with. I hope that these numbers helped any, and again, if you need any more info - just let me know,

Alternators don't have a stud for grounding; they ground simply by being bolted to the engine block. You could add a ground wire from one of its mounting bolts to the chassis, engine block, or negative battery terminal, but it would be redundant. When people add ground wires to Mopar alternators, it is to make a newer dual field terminal alternator (1970 and later) work with a pre-1970 mechanical voltage regulator, and they do this by grounding one of the field terminals (a different thing than grounding the alternator case itself; as I said, the alternator case is already grounded by default, just as soon as you install it).

[Captain D]

Hi Maxim,

I'm not exactly sure what you had referred to as both terminals as being 'grounded.' Basically, I disconnected a lot of stuff, such as: both sides of the voltage regulator (the green field and blue ignition wires), the green terminal wire on the alternator itself, the second field terminal wire on the alternator, and of course, the battery) when taking those readings.

As for the alternator, I had it tested prior to actually paying for it and everything tested out fine. Once installed, it registered at 57 amps and a new voltage regulator should be here by tomorrow. The only thing that came up as being high after a series of tests was the amount of voltage going to the battery. But, the ground wire and stud that I was referring to on the alternator was on my older alternator,  which had the blue wire configuration as pictured on page #2 of this thread. As you may see, the little blue wire and stud were the ones that I was referring to; especially since that specific field terminal seems to have a fiber washer (the washer in between the bolt that holds that particular field terminal in place) to serve as a ground terminal to begin with, it seems.    

Hope that this helps to clarify somewhat,
Aaron

[MaximRecoil]

Hi Maxim,

I'm not exactly sure what you had referred to as both terminals as being 'grounded.' Basically, I disconnected a lot of stuff, such as: both sides of the voltage regulator (the green field and blue ignition wires), the green terminal wire on the alternator itself, the second field terminal on the alternator, and of course, the battery) when taking those readings.

They are both grounded because your meter shows electrical continuity between your alternator's field terminals and its case. When the alternator is installed in your car, the case is grounded, so anything that has continuity to the case is also grounded.

As for the alternator, I had it tested prior to actually paying for it and everything tested out fine. Once installed, it registered at 57 amps and a new voltage regulator should be here by tomorrow. The only thing that came up as being high was the amount of voltage going to the battery. But, the ground wire and stud that I was referring to on the alternator was the blue wire as pictured on page #2 of this thread. As you may see, the little blue wire was the one that I was referring to; especially since that specific field terminal seems to have a fiber washer (the washer in between the bolt that holds that particular field terminal in place).    

Hope that this helps to clarify somewhat,
Aaron

Like I said, I'll defer to Pete in NH. There may be something in those readings that he sees that I don't. You could also try the tests again with your meter set to the 200 ohm range. The reason you were getting all 00.0 readings before was because you had the meter set to 200K range, which is too high of a range for what you're testing (you would use that range to measure 200,000 ohm and higher resistors).

[Captain D]

Okay, I can see what you're referrring to now. But, with being said, I suppose that I wouldn't know which wire (s) to modify at this point on this current alternator.  Just out of curiosity, I thought that the 200k was the correct dial to set the multimeter on to measure the ohms. Would you know which dial I should set it at, what symbol it looks like, etc, and I can always do another round of tests to see what those numbers may be...
Thanks,
Aaron

[MaximRecoil]

Okay, I can see what you're referrring to now. But, with being said, I suppose that I wouldn't know which wire (s) to modify at this point on this current alternator.  Just out of curiosity, I thought that the 200k was the correct dial to set the multimeter on to measure the ohms. Would you know which dial I should set it at, what symbol it looks like, etc, and I can always do another round of tests to see what those numbers may be...
Thanks,
Aaron

You want 200 ohms, not 200k ohms. Take a look at this multimeter - link.

The ohms section on that meter is from about 6 o'clock to 9 o'clock. You can see the ohms symbol (Ω), which is the "upside down U" that was mentioned earlier, and you can see several numbers (200, 2000, 20k, 200k, 2000k). You want to set your dial to 200.

[Pete in NH]

Hi there Maxim,

I did find the symbol on my multimeter that you had noted in your link. Simply repeating the same process, things read as (with the negative battery terminal still disconnected):

- I touched both wire leads of the multimeter together and they registered at 002.
- Disconnected the green wire at the alternator terminal. Put one lead onto that alternator terminal and one to the casing of the alternator for a ground: 002.
- I then repeated the same steps with the second terminal where the new red wire was intended to go, and, it was: from 006 to 007.
- And, I then put one lead on one terminal and the other lead on the second terminal across each other: 007.
- I then had the green wire re-installed at the regulator point and found a nearby ground just to see if anything different would show. It registered at: 025.



Although its not crucial, if mine does require a ground for the alternator its odd that this particular part # didn't have the necessary stud/post already provided to begin with. I hope that these numbers helped any, and again, if you need any more info - just let me know,
Aaron

Hi Aaron,

Okay, now we know what we needed to know!

Yes, the 200 ohm range is the one you needed. When you touched the two meter leads together and saw 002, that meant that the meter leads and connections were adding two ohms to anything you would measure. You simply subtract that two ohms from any reading you make when measuring small resistances.

So, the connection that had the green wire on is really 0 ohms to the case, that is it is connected to the alternator case., no need for a second ground wire.

The second terminal (where the red wire was) is 006 to 007 or really 4 to 5 ohms which is the field winding of the alternator and what I would expect to see there.  THE GREEN WIRE FROM THE REGULATOR should be connected to this terminal.

This is a true 1969 type alternator and should work with the EBay regulator or the old relay/mechanical type if you have a good one. Again remove that RED wire, with a  good regulator you should be all set.

This alternator will not work with the newer Mopar electronic  regulator with out changing out the grounded brush holder.

[resq302]

Pete,

I think what the problem is that when the alt. gets rebuilt today, the kits that are available is the same brushes as the 70 and up units that have the 2 field alt.  Instead of the company cutting the extra connect clip off, they leave it on there so it is a "one part fits all" type of thing.  I had been telling Aaron that original brushes did not have this as the second brush was just screwed right into the housing with no insulator washer at all.  If it did have the insulator washer, then it would not be grounded out to the casing.

Here is a pic of what the original brushes should look like for the 69 and older ones.  Notice the fiber / plastic washer on the one screw for the brush which connects to the green field wire would normally go.

First pic is the sqaure back (2 field) alt. on the right and round back (69 and older) on the left.
Second pic is the close up of the correct brushes.  One with the connector you can see the fiber washer that insulates it from being grounded to the case.
Third pic is of the brushes showing the insulator washer and brushes.

[Captain D]

Hi gents,

First off, I'd like to say 'thank you' guys for all of your time devoted just to help me out - without it; I would have spent a lot more time and money trying to get to the bottom of this issue as there is no one else locally close by where I live as knowledgeable to help me the way you guys have,  .

Maxim - In your link, that is the same multimeter that I have here and I went ahead and turned the dial to the 200 ohm range to double-check those numbers for us, they read:

1.) With the battery still disconnected, I touched the two terminal leads together: 02.1.
2.) With the disconnected green wire at the alternator field terminal, I put one lead onto that alternator terminal and one to the casing of the alternator for a reading of: 02.1.
3.) I then repeated the same steps with the second terminal where the new red wire was intended to go, and, it was: between 07.3 and 07.4.
4.) I then put one lead on one terminal and the other lead on the second terminal across each other: Also, between 07.3 and 07.4.
5.) I then had the green wire re-installed at the regulator point and found a nearby ground just to see if anything different would show. It registered between: 25.4 and 25.5.

Just so that I'm on the same page; I don't need to make a new ground wire - but instead install the green wire (that runs from the regulator) onto the one particular terminal where the red wire was thought to go. Then, remove the red wire altogether (and clip), and install the new regulator when it arrives tomorrow. In your opinions, is that correct? I fought with that clip a little tonight, and even though I haven't got it off just yet...after all the trials we've been through so far, that little clip isn't going to stop me, lol,  . As for the numbers for the 200 ohm reading, what do you guys think about them?

I may have to put in some extra hours tomorrow at my work so I may be a tad late in responding back to let you know how things go, but 'thank you' again everyone (especially Brian, Pete, Maxim) - all you guys truly have a heart of gold and I have nothing but the highest respect for your knowledge, time, efforts, and patience my friends. I apologize that I'm still learning much of the terminology, and it more than likely held us up there for awhile because I didn't know what I was looking at exactly, but I got to say its good learning this stuff so that I may be able to maintain my car in the future and possibly pass that knowledge onto others as well.

Best regards,
Aaron  

[Pete in NH]

Aaron,

Yes, You have it right. The green wire from the regulator goes to the terminal that used to have the red wire on it. again, remove the red wire entirely. And yes, there is no need to ground the other field terminal as it is already grounded. Your readings on the 200 ohm scale make perfect sense as the only thing that has changed number wise is the decimal points were moved over and you got better resolution on the readings.

Brian,

Yes, I agree that some re-builders idea of making a one size fits all alternator can really cause some issues that they should specifically warn you about. At least in the last go around Aaron did indeed  receive a true 1969 round back alternator. But as you say because the re-builder used a non original terminal clip, both field connections kind of looked the same unless you looked very carefully. That was the reason for suggesting the ohm meter testing, to sort out what was really there. Perhaps the board administrators can make a permanent sticky note on this issue out of this thread because I suspect Aaron is not the first to fall into this trap nor be the last.

[resq302]

Pete,

That is exactly why I used a hack saw and cut off that one end of the terminal making it flush like the old brush that I took out.  You no longer have a chance to get it confused.  Heck, even a round back alternator had two brushes, BOTH with the fiber washer.  Once I realized that, I unscrewed the one and made it the field with the direct ground.  Problem solved!   

And yes, I agree that hopefully the mods see this and make it a sticky!  Like you said, I have run into it and as seen, Aaron has also.  Hopefully by Aaron sharing this, others can benefit from his education as well!   

See, Aaron, you aren't just getting help for yourself but anyone/everyone else who either has or might have this issue in the future!

[Captain D]

Hi guys!

I was able to eliminate that red wire and clip, install the new regulator that arrived today, and run only the green wire from the regulator to the alternator (where the red wire was installed at the local garage). The 'great' news is that I now have absolutely 'perfect' numbers (57 amps, 14.6 volts to the battery, and the ammeter is just where it needs to be, which is slightly to the right of the '0') - finally, lol!  . Seeing that put a tear of joy to the eye,  .

Yes, absolutely, I hope that this issue becomes a sticky/point of reference for those who may potentially go through the same headache  . In looking back at this experience, its one of those things to try to see the positive aspect in that not only did I learn more about my car, but hopefully others could benefit from this knowledge as well. The second half of my summer was aggravating at times because while most families were cookin' hotdogs and hamburgers, I was cookin' alternators and regulators well-done without knowing why, lol.

"Thank you" again gentlemen for all of the time that you took to help me out! Y'all send me your home addresses and I'll be happy to send you Christmas cards,  .
High regards,
Aaron   

[flyinlow]

 

[resq302]

Now lets just hope it stays that way.  (So don't go messin' with things!)       Just kidding!  Besides, you gotta keep that car fixed so you can bring it to the National Chrysler Products Club meet next year in Budd Lake / Mt. Olive, NJ!

[Pete in NH]

Aaron,

Great news! It's good to hear everything is as it should be. It was a tough fightbut, you won.

I think we all learned something on this one. In the end the answer is always a simple one once you find it! I think the real thing to remember here is that when you hit a real puzzle such as this one was. Is to take a step back and think your way through the problem by knowing or finding out how the system is supposed to work. Also, having some simple test equipment and making some informed measurements is so much more helpful than shot gun approaches. Unlike newer cars these old systems can almost always be worked through with simple test equipment and a little thought.

[resq302]

Aaron,

Great news! It's good to hear everything is as it should be. It was a tough fightbut, you won.

I think we all learned something on this one. In the end the answer is always a simple one once you find it! I think the real thing to remember here is that when you hit a real puzzle such as this one was. Is to take a step back and think your way through the problem by knowing or finding out how the system is supposed to work. Also, having some simple test equipment and making some informed measurements is so much more helpful than shot gun approaches. Unlike newer cars these old systems can almost always be worked through with simple test equipment and a little thought.

Which is why I would chose an older car over a newer car cause of all the computer related parts.

[Dino]

Aaron,

Great news! It's good to hear everything is as it should be. It was a tough fightbut, you won.

I think we all learned something on this one. In the end the answer is always a simple one once you find it! I think the real thing to remember here is that when you hit a real puzzle such as this one was. Is to take a step back and think your way through the problem by knowing or finding out how the system is supposed to work. Also, having some simple test equipment and making some informed measurements is so much more helpful than shot gun approaches. Unlike newer cars these old systems can almost always be worked through with simple test equipment and a little thought.

Which is why I would chose an older car over a newer car cause of all the computer related parts.

And looking at an old car doesn't make me sad, whereas looking at all this new crap...oh well.

[resq302]

Hey Mods!  Where's the sticky for this?