Strange electrical noise from dash?
 

My 272 seems to have developed an odd problem. When both motors are running and I'm at cruise a strange intermittent screech noise develops. I thought it was the low pressure alarm or radio interference but checked both and it's not coming from them. All my pressures, temps etc are fine.

It's really annoying, the only thing I can think of is I installed an aftermarket fuel gauge and sender, Hardin marine stuff, installed as per instructions. Just the gauge went to zero when this started to occur, I recalibrated the sender and gauge was fine. All connections are clean and tight.

Might it be the gauge creating the noise through some issue with resistance??....anyone experienced this before?...it's very strange.

Yes. The high water alarm is under the dash. It is amazing how loud it is.....ear piercing. You probably have a float switch for the high water alarm going bad. That is what I had.

Is the high water alarm the black round speaker under the dash, near to the steering mechanism?