Alternator charging Question

Not a surprise. Old school rebuilders are just about gone. I see more guys in their early 30's running the show now.

The old round back alternator went away about 4 decades ago. Current model cars come with 200+ amp alternators. The kids in the auto electric business look at you funny when you mention a 37 amp alternator - "You mean a generator pops?"

Your DMM will beep with a continuity test between either brush & the case if one brush is grounded.

Set the meter on Ohms, and test from field terminal to field terminal. The result is the field resistance. That is all the kid at autozone (or canadian tire) will test, because the book does it that way.

Now, test from either field terminal to case ground. If the alternator is isolated field, there will be infinite resistance. If one terminal reads the field resistance, and the other terminal almost zero - the "zero" brush is grounded.

B.