I have an '89 90hp merc, and the warning siren went of on our last outing. The siren sounds constantly with the key in the run position whether the motor is running or not. I found the junction where the three wires from the overheat, oil pressure, and oil level sensors connect to the engine harness, and disconnected all three. I touched them one-by-one to the siren wire, and the one from the level sensor is tripping the siren-with the level almost full. Has anyone heard of these sensors failing-and would it be ok to just leave this one wire disconnected since I keep the oil level full anyway? Any help on this would be greatly appreciated.