Yeah, there is a MOPAR part that makes the alternator work without the ECU. I don't know the part number, but I think Dino does.You'll need an 8-9 volt regulator installed into your MS to get the right voltage to the CrPS.I think you can just hook up the speedometer output straight to the gauge cluster...?
2016 WRX STi Limited (current)2001 A4 1.8tqms (donated)1991 GVR4 #1933 (sold)old.dsmregistry.com/detail.php?carid=218 (dismantled)