OK, I have installed a new front end and engine wiring harness during my big block conversion. New alternator, new regulator. The battery will drain overnight. When installing the battery cable, the regulator will click. I reinstalled the original regulator, same thing. It's grounded, the wires on the new harness are connected correctly....or as illustrated. This is a period correct 396 with points distributor. Everything electrical works as it should expect for the overnight (new) battery drain.