Black box makes noise over 3500 RPM

[dielawn]

Hey Team,

I am out on the new BU this weekend, and I noticed that there is a high pitch WHINE Sound, that is coming from under neath the dash. While traveling over 3500 RPM ( was going home and traveling over 25mph) I had a friend take the wheel while I layed down underneath the dash and listened to where the noise came from. Im fairly certain this box was making the noise:

Obviously it says REV8 and is meant for the stereo? But I am not even sure exactly what this box does. Do you think this is something that can be fixed? Or should i just have the dealership replace it? I am attempting to fix any small issues i notice myself, because I am trying to avoid bringing my boat into the dealership (boat is at the river house 3.5 hrs away.) until the end of season. All the connections seemed to be snug and tight, i did notice also that there are power cables + and - connected to it, which could be the result of the noise. Any suggestions?

[foiler1]

I get the same thing from under my dash. I always thought it was wind catching something. When you hit a bump, the pitch changes. I am interested what it is

[Fman]

Could it be your vented loop under the helm?

[Bawshogg]

I would bet on air rushing down the fresh air tubes before the box as the cause. You cannot unplug that box while underway.... Or at least it would not be recommended. That's your main fuse panel, or medallion box.

Put your boat on a fake a lake, unplug the trans engagement solenoid a and run her up to 3500 rpm. Betts the noise isn't there.

[dielawn]

I get the same thing from under my dash. I always thought it was wind catching something. When you hit a bump, the pitch changes. I am interested what it is

Yes! When going over rollers or a wake for that matter, it would make the wining sound and change pitch, but it doesn't make sense, that it would be wind causing the noise.. its in an enclosed plastic box? It sounds like "manufactured" sound not a natural wind hiss...

[Fman]

You could fill up your bow and center tank, run it at same speed and rpms to see if that eliminates the vented loop theory. I also noticed a similar noise on my vlx at 32-35 mph, but it does not always do it. I figured it was the vented loop having air run through the empty ballast tank/vented loop.

[Bawshogg]

That's a good probability also. If the inlet gets above the water level and is exposed to airflow that could possibly cause it too. I think the bow loop is under the helm and belly tank is in the observers compartment.