Has anyone had a problem with an 2008 Gen 8 Accord with the headlights flaring up at times. Seems to occur in time with the altinator regulator cutting in and out.

 

Alternators have replaceable brushes with diodes built in. It might be that a brush is worn or defective and isn't making contact. I would start there.

Check all conections, from alternater,battery etc., both positive and the grounds. Make sure all are clean and tight. Loose and dirty conectins will cause more problems then you think possable and make electrical systems act really strange. Check the simple[easy] things first. Make sure grounds are good, because if you have a bad ground then all the power in the world will do nothing.