Mercury – Oil Pressure Sender, 80 PSI | Instrumentation | 815425Mercury Oil Pressure Sender, 80 PSI Instrumentation 815425 Overview On a MerCruiser, the oil pressure sender is one of those small parts that can make the whole engine seem like its acting up when really the senders just tired. A bad one will have your gauge flickering, dropping to zero, or giving readings that dont match what the engine sounds like. Swapping in this OEM sender brings the gauge back to giving steady, believable numbers so youre not