[scholls]

2017 MKC 2.3T. After the vehicle is turned off, there's a faint electric motor/fan humming sound. It seems to be coming from under the left rear passenger seat/rear compartment. It stops after 5-10 minutes. Then, when any door is opened, the sound starts again. This occurs when no power has been applied, ignition or auxiliary. Just opening a door it starts after about five seconds. What could it be and is it abnormal?

 

[Skinsfan]

I am recently experiencing it as well its coming from my sub woofer however mine is definitely loud
I think it killed my battery (replaced it)
Same thing though everything is turned off and when it starts occasionally the dash board reactes funny
2018 2.3 mkc

 

[copbait]

2017 MKC 2.3T. After the vehicle is turned off, there's a faint electric motor/fan humming sound. It seems to be coming from under the left rear passenger seat/rear compartment. It stops after 5-10 minutes. Then, when any door is opened, the sound starts again. This occurs when no power has been applied, ignition or auxiliary. Just opening a door it starts after about five seconds. What could it be and is it abnormal?

My guess would be to check your amplifier if you’ve got a THX system

 

[Lancdoc]

My guess would be to check your amplifier if you’ve got a THX system

I believe there is a fan on the subwoofer (correction - amplifier) with the THX system that cools it, I suspect that is what you're hearing.

 

[scholls]

Thank you.

 

[copbait]

I just noticed I said sub - I meant amp!!

 

[Tracy]

That is correct. Where the spare tire is above that left driver side there is an amplifier and then there's another powered computer controller that's near there on the right. They have both have cooling fans that run for a few minutes to make sure the amp/controller are cool after the keys are off. Electronics do not like heat and for that measure I keep a sun shade over the windshield during the summer to make sure the display doesn't get overheated.

 

[scholls]

Thank you to all. Our dealership confirmed the amplifier needs to be replaced.