Roundback vs. Squareback alternators?

[Mattax]

What we're saying is that this one was already modified by the builder with the circled brush grounded.
Shouldnt have to change anything

Check the field as follows: Take a continuity tester (powered light, or an ohm meter). Place one lead on the field terminal and the other on the housing. It should light up, or measure between 2 and 4 ohms.
Then remove the circled brush. Retest the same way. It should not light up , or resistance will show as maximum or infinate.

The alternator pictured below was at some pointed hacked to make it an isolated field alternator.*

Who knows what it is now.
Test the rotor connections the same way as above.

*See the Identifying Chrysler Alternator thread for more info about how rebuilders hack alternators.

 

['Cuda_ragtop]

I upgraded my square back to 80A in 2014 for $82.01 shipped.
Still works great.

I also ran a #8AWG charge wire direct from the alternator, bypassing the firewall bulkhead and amp gauge to the positive battery post on the starter relay.
Not the complete Mad Electrical bypass, just an added a direct charge wire.

I use a digital volt meter plugged into the lighter socket. It has dual USB charge ports too.

Stock generic photo from ebay...
My typical voltage when running is ~14.4VDC
Your mileage may vary...

Price for the alternator upgrade kit is now $104.95
HO7005R Chrysler Square Back Alternator 80A Upgrade/Repair Kit

Not sure how cost effective today compared to other options but it has worked out well for me.

 

[SixgunSal]

What we're saying is that this one was already modified by the builder with the circled brush grounded.
Shouldnt have to change anything
View attachment 1715899847 Check the field as follows: Take a continuity tester (powered light, or an ohm meter). Place one lead on the field terminal and the other on the housing. It should light up, or measure between 2 and 4 ohms.
Then remove the circled brush. Retest the same way. It should not light up , or resistance will show as maximum or infinate.

The alternator pictured below was at some pointed hacked to make it an isolated field alternator.*
View attachment 1715899848
Who knows what it is now.
Test the rotor connections the same way as above.

*See the Identifying Chrysler Alternator thread for more info about how rebuilders hack alternators.

How did you know that..that it was already modified by the builder with the circled brush grounded. I have taken the washer out of it and put it like that in the car...maybe thats why it isn't charging. I will need to get one of those tools from Amazon to check it like that. I thought I read somewhere that Dodge put out isolated field in 70 and 71, is that correct?

Also, I guess I'm going to have to order that washer to put it back in the slot in the alt, I can't find it now. Anyone have one to mail me if I give you my address?

 

[Mattax]

How did you know that

Because its the only reason the builder would have cut off the terminal. @Joey4speed told us this was in fact common practice with some.
Do we know for sure that is what is going on with this particular alternator? No. That's why I suggested testing for continuity or resistance.