Topic: Very poor wiring diagram.

[lucky]

I need some help from the experts.
I am restoring a CB750 and bought a new wiring harness (1975)
he bike is a 1978.
I bought a Rick's Motorsports regulator/ rectifier unit.
But there were more available parts for the earlier models.
Everything was plug and play until I got to two items.

There is a short pigtail coming fro from the solenoid that has a plug with two female prongs facing the same direction. It has a red wire and a red and white wire.
I do not know what it plugs into. The wiring diagram just shows a black rectangle with no name on it. (see diagram)
What is it? (black rectangle)

[magconpres]

The black rectangles are the connectors in the harness.  In your case, the black rectangle is just the unused connector you are asking about.