Last Friday while on a fishing trip a continuous, ear-piercing alarm came on shortly after being under way. The alarm is located very close to the ignition switch under my console. The alarm stayed on constantly when the motor was running. Everything was working properly; motor was not overheating, strong stream of water coming out of p-hole; battery was at 12.9 volts, no water in bildge, but oil was very low in my oil injection tank. After filling the oil tank the alarm still rang, but everything was working. On the way back to the dock, the alarm qiut, then randomly came on and off again, seemingly with the swells of the bay. Rolling the dice, I disconnected the wire to the alarm to drown the sound and had a very good day of fishing with no mechanical problems with the boat. When I returned home, I reconnected the alarm wire before flushing the motor and the alarm did not come back on. Has anyone experienced this? Any ideas what to look for? The motor is a 2002, 150 hp Johnson outboard with carbs.