I've had a little google around...
From what I can see, on the new rectifier, the 3 black wires are generator wires, and all carry alternating current, so it doesn't matter where you splice these into, so long as they go to where the old yellow one's went.
That's the easy part.
Then the black & red is battery 'hot' (+ve), and black & white is apparently negative/ground. Why there's a pair of +ve & a pair of -ve wires, I do not know though.
I'll try to double check things, but that's where my thinking is at the moment
