Yes, I remember now, that when I had the spark problem before, when everything was stock, the grey wire was only pumping out 5.5-6v or so. Maybe I need to have one wire carrying the 12v going in to the resistor, which acts as a voltage divider and the two wires coming off share the voltage? Will speak to my Dad (he knows a bit about electrical stuff) and see if that's a logical train of thought. Would you be able to check the voltage of the Brown/White wire going in as well? Just out of curiosity.I don't think the M Unit can mimic the original keyed ignition switch.
The original switch connects three wires, and the resistor that's soldered in parallel to two of those wires limits the voltage that runs down the grey wire to the CDI box.
The CDI box either senses that correct voltage, or opens a gate based on that voltage, and spark!
So far, that's my limited understanding of what happens, could be right,, could be wrong, dunno!
Maybe the following will help the OP re-work the system he has to match the same effect:
View attachment 54101
That's a 2003 Kawasaki EX500, GEN2, more or less stock.
Key on: battery voltage is about 12.5 volts; voltage at the grey wire as it enters the CDI box is 5.85 volts.
So, I guess the resistor installed in parallel to the two ignition switch wires reduces the grey wire voltage by about half.
I don't know if there's another way to accomplish the same effect, maybe OP can puzzle it out.
Otherwise, I suggest you send this query to a high school Electronics class and ask them.
When you get it sorted, let us know, Cheers!
EDIT: He said he thinks that idea will work. + Crude picture to show what I mean in the above explanation.