Crunching noise

[Irish Mist]

Hi
Having an issue..
2011 R29 on shore power.
This happened a month ago and now at 1AM and just now..
I know a fair bit about electrical and other stuff.. Hoping by chance someone may have had this issue and can share.
I hear a noise like paper crumpling for 1-2 seconds..it stops then a high pitched sort of like a quiet alarm starts..
Does not sound like electrical arching .. more like paper being crumpled.. I did and still suspect electrical but everything works no flickering no electrical smell I opened electrical panel and checked inverter and no electrical smell anywhere .. Can not pinpoint exactly where the noise is coming from.. always stops before I can locate it.. At first I thought and it still maybe the inverter.. but sounds like it’s in the panel area..
I am in fresh water so it is not shrimp or oysters under the boat..
it is a real mystery.
Thank you for reading.

 

[ChrisJ]

Hmm, I'd check the automatic bilge pumps and alarm. I recently replaced a faulty alarm siren with a new one because the high pitched alarm was barely audible.

CJ

 

[Irish Mist]

I am thinking now it may be the smart plug I have the heater plugged into so Alexa can control it. Going to remove it and see if It happens again. Only 30 amp power so Alexa is nice for shutting heater on and off for power management.. Fingers crossed this is it as it is the strangest noise I have heard.