OMC Alarm Horn
Posted: Mon Nov 02, 2020 3:06 pm
[I] [NOTA BENE: the moderator has added a sentence SUBJECT to most of your your SENTENCE FRAGMENTS] have a 1996 Johnson 225 Ocean Runner. [The engine] has been a reliable engine [in 2018 and 2019], [but on the] last trip out [in 2020] the warning horn was faintly chirping[, that is, the horn was] on for a second then off for a second[.] I throttled back to idle speed, [and the warning] horn quit[,] but [it] would come on again (faintly) at a fast idle, [amd] then get louder as I increased speed.
[There was] plenty oil in the tank, and the engine seems to be putting out enough blue smoke to make me believe it is still getting oil.
[I c]hecked out the horn in the binnacle: it had two [violet] wires connected together, one tan [wire], and one black [wire] to ground. The epoxy potting was melted [and] trashed to the point when I pulled on one of the wires it came out of the horn fitting[amd] all.
[I r]eplaced the horn, all I could find was a two-wire setup [with one violet and one tan wires]. so left the black [wire] hanging there.
As soon as I had everything hooked up the horn sounded, but this time a steady BEEEEEEP. Then I disconnected all the sensors--overheat and oil level--to start testing.
[I t]ested the overheat sensors at the cylinder head[. T]hey both seem to do as they should. As soon as I connect the oil level sensor the alarm sounds with a steady BEEEEEEEP.
[Does this description] sound like the oil level sensor has given up?
One thing I don't understand: I did a continuity check from the tan wire going into the oil sensor and the black coming back from the sensor, [and I] got no continuity. These wires eventually get bundled into the harness and disappear under the flywheel somewhere. Could it be something has gone bad under the flywheel, fusing these wires together somewhere and triggering the horn?
[There was] plenty oil in the tank, and the engine seems to be putting out enough blue smoke to make me believe it is still getting oil.
[I c]hecked out the horn in the binnacle: it had two [violet] wires connected together, one tan [wire], and one black [wire] to ground. The epoxy potting was melted [and] trashed to the point when I pulled on one of the wires it came out of the horn fitting[amd] all.
[I r]eplaced the horn, all I could find was a two-wire setup [with one violet and one tan wires]. so left the black [wire] hanging there.
As soon as I had everything hooked up the horn sounded, but this time a steady BEEEEEEP. Then I disconnected all the sensors--overheat and oil level--to start testing.
[I t]ested the overheat sensors at the cylinder head[. T]hey both seem to do as they should. As soon as I connect the oil level sensor the alarm sounds with a steady BEEEEEEEP.
[Does this description] sound like the oil level sensor has given up?
One thing I don't understand: I did a continuity check from the tan wire going into the oil sensor and the black coming back from the sensor, [and I] got no continuity. These wires eventually get bundled into the harness and disappear under the flywheel somewhere. Could it be something has gone bad under the flywheel, fusing these wires together somewhere and triggering the horn?