Merc Optimax 150 SmartTach & System Monitor not working


New member
[h=3]I have a Merc Optimax 150. There is not a tag on the mounting bracket but there is a sticker on the starboard side of the engine:
Model#: 1150D83YD
Serial#: OT207149

There is a SmartTach #79-859067 V2.80 and System Monitor #79-879896 V1.01. Neither gauge powers on when the ignition switch is turned on or when the engines are running. The harnesses are connected.

I'm not sure if I need replacement gauges, ignition switch, etc. Do you have any recommendations? Thank you.[/h]