1986 Johnson 90 hp alarms

[gw1966]

I have an alarm that goes off when I am idling around (trolling), it is coming from my control box. I don't know if it's my oil injection alarm or my overheat alarm, it's a steady sound, not intermittent. I fired it up last night on the ear muffs and it kept going off, but I fired it up tonight and it wouldn't go off at all. My water pump was replaced 2 years ago.
Can you tell me what the alarm sounds like for the oil injection?
Why does this only go off at idle and not on plane?

[RUSTY63]

Welcome to the BBC.

The No Oil horn is a intermittent horn, half second on half second off.
The overheat horn is a solid horn.
The low oil is a 20 or 40 second on short horn.

Follow the wires from the oil tank to the motor and disconnect them, see if the horn stops sounding.