Amazon - Medallion - Compra Medallion. AdSpedizione gratis (vedi condizioni) Medallion Tachometer Installation Page: 1 - iboats Boating forumsts›Forum›Boat Repair and RestorationRe: Medallion Tachometer Installation ING-Sender grey wire GRND-Black ground wire light- Blue wire Not sure if you use the purple wire here. Medallion tach wiring | The H.A.M.B. wwwpyjournal››The Hokey Ass Message BoardMedallion tach wiring. Not sure but I think Medallion was bought out by BorgWarner Instrumentation some years ago. Might check with them too.