Zenmoto, your discription gets a little confusing but you've got it right, the AC reg gets wired in parallel with the light. If it's working properly the headlight will stop getting brighter at about 4000 rpm.
XR650R Plated Supermoto
XR628R Plated and highly modified
CR500R Still rips after all these beers
RZ350L Kenny Roberts Special
BMW R1200GS Adv Kind of a space ship