GS550 not charging
 

GS550 - Stator tested out good. Leaning towards rectifier. With headlight removed (Always on other wise) battery reads 12.4~ at idle. And won't go higher than 12.7V revved. With headlight on Im getting 12.1~ at idle. RR is wired directly to battery and stator. 5 wire aftermarket.

Ive heard about some RR loop to headlight. Wondering how to cut this out to rule out any wiring issue before buying an RR. Anything else I should check?