Do like Wrenchbender describes but if it doesn't charge, check continuity of the field wire before buying a new regulator. I didn't and it turned out to be an internal break in the wire.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.