Just re-read your posts - if you painted the engine that won't help anything, the return path for the generator itself is through the block. Everything has to be clean and tight electrically speaking. If there is paint on the generator mounting pads, brackets and such, that might do it.
High resistance is especially a problem for generator systems. Check the regulator itself, too, it is grounded on the fender apron on mine, but still has a dedicated factory ground lead going to it for this reason.
Sent from my iPhone using IB AutoGroup