Well, NUTS!

I put on a new connector harness and new regulator.
Verified that the regulator is wired correctly.

Charge voltage measured at the battery came down to a more normal 15V as read on an analog meter.

But the amp gauge still bounces, and now my fuel gauge bounces too!

I've lost my light for the day, back at this tomorrow.

1957 Chevy 3600

At these prices I want my gas 100 octane, leaded, and my windshield washed!