MX5 dash lights , electrical issue

[Drummajor]

Guys, any electrical gurus out there?
My mk2 MX5 now has the super charger fitted and megasquirt2 Ecu .
Those also in the know know that you have to fit a mk1 alternator as it is self regulating as the mk2 alternator is regulated via the Ecu (which has now been removed to fit the mega squirt)
All works fine , however I do not any longer have the battery charge light on the dash which should go off after a few seconds .
Is there a way around this ? As the mot man may wish to see it.
Many thanks