My boat has a 90hp Johnson 1985 outboard.<br /><br />I just bought a collection of OMC Gauges on Ebay. They came without senders. My new gauges are Oil Pressure, Water Temperature, Trim, Voltage, Tach, Speedo. The existing guages in the boat are a tach that doesn't work, a speedo that does and a trim gauge. Both the old and new match!<br /><br />So my questions, what kind of sensor do I need for the water temp? Where do I mount it? Could there already be a temp sensor or were they only put on with the gauge?<br /><br />Can I use the Oil Pressure gauge for anything? Can it be adapted to be a water pressure gauge?<br /><br />Thanks<br /><br />Dave