Well I have more goofs, and I have discovered the wire harness that came with my motor has a lot more wires than the motor has functions. So now I am changing one of my gauges, and am jury rigging the alerts built into the tach I bought.
When I first picked up the motor I went through the diagram for the wire harness and identified that it had a trim signal connector, and the Suzuki Diagnostic System connector which provides a check engine, over temp, over rev, and oil pressure light. So based on this I purchased a tach that had the 4 suzuki monitor lights built in (extra$50) and a trim gauge. Since this is the power Tilt version I wanted to have some idea of where the trim was while cruising etc.
Well, now that I hung the motor and wired things up to test everything I have found out that the 9.9/15/20hp model does not have a trim sending unit and does not support the Suzuki Diagnostic signals. This harness is also used for the 25hp and up, which have these extra functions. The motor has these features but it only flashes the warning light on the front of the motor and does not send these up to the helm.
So I am returning the trim gauge and I will I stall a voltmeter instead in the 2" hole. And the Tachometer I am going to keep the same. The wiring diagram shows that the oil pressure switch signal is sent to the remote control to trigger the buzzer when oil pressure drops. So I am going to jump this wire to the oil pressure light on the tach, so I will at least have one of the warnings lights functional.
But on the bright side, since the harness has these extra wires that do not go anywhere, I can use them to run my lights and bilge pump. So all my wires will be in one nice clean bundle.
lesson learned; make sure the wiring harness you have is specific to your motor. If it is a harness that is used for multiple models, it may have a bunch of wires you don't need.
I am going to strip it down and shorten it up to fit exactly what I need since the harness is about 16ft long and 6lbs.
