firstly glad we are getting somewhere!
But sadly you worry me when you talk of the black / white loop!
The way you describe it is that it is one wire running in a loop and joining back to itself while it swings in the breese.
If this is the case you have it wrong!
You need this loop black/white wire and you need to look dirrectly behind the tacho gauge at the wiring harness, here you should find taped in a bit of coloured tape another black/white wire, it will have connections in it , and to this you join the looped black/white wire.

Now the other wires.
I dont know what the box is as i cant see it.

Simple and easy way to tell you how to do it is :
The black wire connect to ground.( earth, body etc)
The red / yellow connect to 12V ignition supply( 12volts when the ignitiion is on and 0volts when it is off)