alarm randomly going off. trying to track down source

[turbocorrado]

It could be the sensor but since you plan to run it again, If you didn't have a chance last time out then do yourself one last favor, connect the sensor back up and unplug the 2 connectors to the ignition control module, check the connectors and reinstall them and see if the horn come back.

Happy boating. :usa::usa2:

i did check the connectors on the icm and they were fine, no corrosion or loose wires

 

[turbocorrado]

To test the sensor check for continuity. That switch is normally open (off) til 195 degrees for carb applications, and higher for EFI. If your ohms go infinite (approach zero) or your continuity tester beeps below 195 the switch is no good. Or if you use a powered test light same thing. If it lights cold it's not working right.
You didn't mix up the temp sensor with the temp alarm switch right? They look pretty similar on my boat.

il ohm it out next time i go. the sensors have different connectors on my boat so i couldnt mix them up

 

[NHGuy]

Yea, I did bassackwards the infinite stuff.

 

[nickmo]

I had this problem a couple of seasons ago. I changed all sensors and even replaced the oil reservoir. When I disconnected the wires from the ignition module and cleaned the connectors, that solved the problem. They weren't really dirty either.