Not charging

Turn the ignition on, not started.
Take a piece of iron, screwdriver, wrench, whatever, and pass it in front of the alt pulley.
If regulator, brushes, and wiring are good, - there will be strong magnetic attraction to the alt prlley/shaft.
No magnetism, - brush or regulator prob.
Strong magnetism, not charging, - is likely rectifier. (Diodes).
Quick, side of the road check.