High pitch noise from engine compartment

[Mikewhfd]

I parked after a short drive of maybe 3 miles leaving work and came out about 30 minutes later to wash the truck. I heard a high pitched noise that I thought was coming from my neighbors house. However I realized it was coming from under the hood. I opened the hood and took a video. I have no idea what it is or the exact location it’s coming from. Once again the dealer claims they’ve never heard that and I’d have to bring it in.
I can only assume it’s some sort of component de-energizing but I’m at a loss. Can anyone give an opinion on what it may be. Thanks

 

[Mikey Swift]

Probably the headlight ballast.

 

[Mikewhfd]

I didn’t realize the video didn’t attach .