I have also MC21 you should looking for the PGM III unit.
You can find it at the end of the bike close to rear stop. The PGM III have 2 connectors one black and one white. You should be do a easy conductivity test between Orange/Blue wire at the black connector and the Black/White wire also at the black connector that goes into the unit. If your multimeter beeps your bike have the wire splice done correctly, but if not beeps there is no wire splice done to your bike.
Hope this helps.

Greetings George.