Humming noise

[Smoke On The Water]

I recently pulled boat out of storage and parked in driveway. As always I plugged battery charger in. Today I was working on the boat and noticed a humming noise coming from my 2015 Yamaha F250. To me is sounds like the fuel pump trying to pressurize the fuel system but i am not sure. I turned off the main electronics switch selector on the dash noise went away. I then turned to battery off as I was trying to reset the system to no avail. It should be noted that I winterized the boat last year and changed all filters and water separator so the fuel system may not be full. After undoing this process, the humming came back.

[99yam40]

bilge pump maybe
or T&T motor

[Smoke On The Water]

Took cowling off and noise is coming from the motor top forward it seems.

[fairdeal]

usually the humming noise, with key on, is the electronic throttle body
(and perfectly normal)

but I don't know what to make of any connection with
"main electronics switch selector on the dash"

[Smoke On The Water]

It seems to be coming from the throttle body area. Never heard it before. Could it be because the fuel system is dry and not pressurized? The the fuel filter is empty as this was replaced during winterizing? I do have Garmin networked to the outboard which comes on with the electronics switch. To get it to stop I have to throw the main power switch or turn off the electronics switch. The key is not even in the ignition switch?????

[DennisG01]

If the float switch inside the VST tank is low (no fuel), then the HP pump, I would imagine, is running? If this is the case, that's not good for the pump. You could disconnect it. Normally, the pump stops after a few seconds - but that's with fuel in there. Not sure what exactly happens with no fuel... Maybe someone can verify this, though?