High pitch ringing noise coming from inside cabin

[sgoulette]

I have a 2011 ford explorer with roughly 190,000 miles on it. Just recently, there has been a constant, high pitch ringing sound inside the cabin. It’s like a dog whistle, and it only goes away when I rev the engine past 4000 rpm. It is only on when the car is running, and it continues even when I turn the stereo and climate off. It’s starting to drive me crazy and I’m wondering if anyone has any input. Thanks

 

[Mbrooks420]

Do you have 120vac power in the truck? There was an issue with the power inverters on the older models making a humming sound inside the cab.

 

[MrPlat]

Do you have 120vac power in the truck? There was an issue with the power inverters on the older models making a humming sound inside the cab.

I think it's behind the passenger kick panel. I test drove a few Explorers before buying mine, and they all had this whine. All of them from the amp hidden in the kick panel.

 

[peterk9]

View attachment 446036

Peter

 

[peterk9]

Peter

 

[PlatinumOwner]

How to: - Replacing the 110V Power Inverter

This guide details removal and replacement of the 110V 150W power inverter. The latest part revision is GB5Z-19G317-F and appears significantly changed from the original 2016 inverter. The inverter is located in the lower right passenger side behind the glove box. Step 1) Disconnect the...

www.explorerforum.com

 

[J_C]

If the inverter is expense, but can be non-destructively opened, in the past I've had good luck quieting down coils on SMPS (switch mode power supplies) by coating the coil windings with epoxy... something non-conductive/non-ferrous, not iron fortified like JBWeld is.