Help with alternator wiring issue

Just went through this alternator thing with an old A and a new alternator. Mopar made 3 (used 4) different alternators in the early years 60-80. Essex first model looked just like the roundback alternator, then Mopar started making it themselves- that went through 70 ish then they added a horizontal field terminal to the old roundback design and used an electronic regulator with it , then the squareback dual field alternator came out from 71 ish to 80 and beyond. Easier to repair as the innards were bolt in, no soldering to repair. The round "1 field" alternators (all have 2 fields but the early ones 2nd field was grounded internally) had a variable positive voltage source as the exciter (blue wire) from the regulator, it turned the alternator + voltage on and off to keep the battery @~13.5V. The newer 2 field alternators (both late round backs and new sqaurebacks) had 2 fields that were insulated from ground. The first exciter was ignition 12V constant blue wire, the second field was a dark green wire that was a variable GROUND from the electronic voltage regulator (it needs a good case ground when you mount it, be sure to use star washers and scrape paint). These newer style alternators used a variable ground that was safer and more reliable than a points style on/off positive voltage regulator. You can use the later 2 field terminal alternators on an older Mopar by grounding one of the field terminals, either with a jumper to ground or taking the mica insulator washer out of the terminal and shorting it to the grounded case. Conversly, you can use an old alternator with a new system by adding the horizontal brush terminal where the ground lug is located (sort of depends on the rebuilt unit your working on as it may or may not have this provision, but youll still have an anemic 35A alternator). Hope this revival of a topic helps some one besides me looking up the info.

PS> brushes work on both models, L shaped brush is the one you need to add to the older alternator opposite the ground brush. There was a threaded socket on my Rebuilt unit for this 2nd field terminal. Remove ground brush and your set. Here is a few pics of the conversion: click thumbnails to make 'em big.

https://picasaweb.google.com/68pishta/Alternator?authkey=Gv1sRgCL7w6e2c-u_Sew&feat=directlink