Twin 4.3 audible alarm

[Monterey276]

I have had an intermittent problem with my audible alarm, going off randomly for the last few seasons. Sometimes it is a sustained beep and other times it just chirps for a second or two. Sometimes it never comes on at all. It only comes on when the boat is under load (around 3k rpm or higher). Once I throttle down it goes off immediately. The temp and oil gauges always read within normal operating range and the drive oil reservoirs are full. I recently tried isolating the senders by disconnecting them one at a time and then driving the boat. I thought I had it isolated to the port engine temp sensor which I replaced but sure as ****, next time I went out, it came on again. Any suggestions for further troubleshooting to find the problem? It is twin 4.3’s carbureted

 

[Bondo]

I recently tried isolating the senders by disconnecting them one at a time and then driving the boat. I thought I had it isolated to the port engine temp sensor which I replaced but sure as ****, next time I went out, it came on again.

Ayuh,...... Welcome Aboard,........ That's how it's done,......

One of them, or their wiring is goin' to ground, triggerin' the alarm,.....

 

[Monterey276]

Ayuh,...... Welcome Aboard,........ That's how it's done,......

One of them, or their wiring is goin' to ground, triggerin' the alarm,.....

Yea well, I’m looking for suggestions on how to actually test the wire next. I suspect it’s a frayed wire but I’m not really sure what to do with my multimeter to find that. My next plan is to drive the boat with only one engine running at a time. Hopefully that alarm is only chirping with one or the other which cuts my troubleshooting in 1/2. But I don’t know how anything is wired up once it leaves the senders. It’s all bundled together and then goes to the alarm in the dash. Are these 2 entirely separate alarm systems? Does each engine have its own independent audible alarm? Or are they both wired back to the same alarm? I haven’t taken the instrument panel out yet to search for that. That’s on my list for next round of troubleshooting. Also, is this the same buzzer/alarm for when the key is turned on?

 

[alldodge]

Each motor should have it's own alarm
What is the motor serial number?