Z1 reg/rect upgrade question

I thought upgrading my Z1 regulator and rectifier to a new combination unit was something I could do myself but I guess not. I have a black and a white wire coming out of the new unit, I know black is ground and white goes to battery (which is orange with the fuse in the photo.) when I connect these there is no power. But now I see an extra white wire coming from the back of the panel. I dont remember where this was, and I dont want to set my harness on fire for lack of knowledge. How do connect this?  

All three of those connect together. The male 6.3mm terminal you have circled in red is from the sub harness in junction panel but routes out to the red plug that goes to the Main harness when plugged in. This White wire goes directly to the Key Switch. Originally the rectifier had a double female 4mm connector on another white wire which took care of this.    

Thank you!