115 ceto digital tacho ,trim,tilt gauges1995

does anyone know what to do with my tacho's when the lcd is buggered? I know the previous owner tried to convert over to new gauges and harness but didn't work apparently the old sendors use two wires the new ones three?I have hooked up analouge tacho's by using the green wire but unsure wether what wires I need for alarms and trim,tilt? Also does the gauge need to be genuine for the engine system checks and faults?? thanks If anyone can help

[boats.net]

6Y5-8350T-82-00 Multifunction digital tach will work on 1994-2004 motors with 68F-82553-70-00 trim/oil harness(harness has 2 off colored square connectors on engine and tach end of harness) which should be the harness that is on your motor.