Alternator Roundback . couple questions please.

Not sure when they went from round to squareback. About 73, 74 I think

We need a photo, why? Because some lazy rebuilders CONVERTED 69/ earlier alternators to "isolated field" That is the proper name.

If it is actually a "real" isolated field, the first ones came out in 70, with some rare "late 69" ones which I've never seen, except pictured on the internet. The earliest versions had THREE regulator terminals, which is why the 70/ later regulator connector is shaped the way it is

This one here (click the link, too large to post) seems to be an oddity. While it appears to be "factory" isolated field (dual field) it ALSO has a place (marked grd) for the 69 style grounded brush. I don't know if this is Chrysler, or aftermarket

http://www.urqualitysolutions.com/images/36-7019-3.jpg

Here's another "oddity", same or similar to above......two isolated brushes, and a place for a grounded brush. This one is set up for a grounded brush (on left) and is missing the second isolated brush (yellow circle)



Below is what the definitive 1970 / later roundback isolated field should look like.......two isolated brushes, and no place to mount a ground brush



Below is the hated, hateful, POS "rebuilder" modified. This started out being a 69/ earlier with a grounded brush. Rebuilders drill the hole shown here at 12 O'clock for the second isolated brush. This one still has a grounded brush



Why post all this? Why does it matter? BECAUSE IT CAN be dangerous. Some of these "came through" with a grounded AND isolated brush, or with what 'appears' to be two isolated brushes. If you hook the blue ign wire to the grounded brush, "smoke happens."

If you are lucky and get the blue ign hooked to the other one, you are faced with horried overcharging, as the alternator is at "full output.