Electrical Issues LX470

[100seriesmike]

Hi all,
My 2003 LX just developed a constant high-pitched noise inside the cabin, coming from the left side of the dash/driver footwell. It's a super high frequency sound that's present while the truck is running. When I hit the hazards, or the right turn signal, the high pitched noise will alternate with the blinking of the turn signal. If I leave the hazards or the right turn signal on long enough, the high pitched noise will go away completely for a few seconds once the turn signal is off, but then come right back. Does anyone have any idea what this could be? Literally happened overnight - I'm stumped. Thanks all.

 

[Trunk Monkey]

Any signs of water intrusion in the footwell or on the fuseblocks?

 

[100seriesmike]

Negative. Nothing is wet and I don't see any water anywhere even with the lower trim removed so the fuse blocks are visible. Windshield isn't original fwiw.

 

[100seriesmike]

Worth noting though that this came up following a heavy rain storm.