What you really have to polorize is your generator. Do so by disconnecting the FIELD terminal wire at the regulator and momentarily touch this wire to the BAT terminal of the regulator. NEVER use a jumper wire to keep from disconnecting the fieldwire at the regulator. It’ll ruin the regulator in a hurry. You'll get a spark when you touch the field wire to the battery terminal on the regulator. That's OK. As soon as you get the spark, take the wire off. In that short instant, the current will create a very small residual magnetism in the generator coil so that it will charge correctly when operated.
After my '47 Sedan sat for 31 years by my mothers house and we started restoring it, I had no idea about positive ground so when we put the battery in we hooked it up negative ground just like all the cars I knew. We drove it that way for three years. Everything worked fine except the battery gauge. It read backwards (charging when it should have been discharging and discharging when it should have been charging.) I had no idea why until I had the engine rebuilt. The mechanic said, "Oh, by the way. Did you know you have your battery hooked up backward?" Duh. I didn't know. After he finished the engine and hooked everything back up he just had to repolorize the generator as I have explained above and all was well.
P.S. If I hadn't told the guy that rebuilt my radio that it would be negative ground, it wouldn't have worked because the original ******** in it will only work with positive ground. Since he put a ******** in it that didn't care what was grounded it didn't matter, fortunately.
