Re: Testing warning horns on outboard?
Just went through that. My oil alert died and I tested and installed a used one.
1. Should be a power on diagnostic beep, usually 1 long and 2 to 4 short.
2. With engine idling, if you disconnect the motion sensor, it should alarm.
3. With engine idling, if you disconnect the ungrounded tank wire and ground it, it should alarm.
Once there, the power on diagnostic should be reassurance enuf.
hope it helps
John