I had reason to be listening to the radio in my new-to-me 2018 Fit EX, had the car turned off so no engine noise, and noticed a hum as I listened. Did some testing and it seems like the stock head unit has a cooling fan, could that be true? Anyone else notice this?

 

I've heard that in my 2020 Fit Sport.

 

 

Thanks! (it's a bit ironic that 'quick replies' have to be at least 10 characters!)

 

Have never noticed, but we have a ‘15Lx, May not apply

 

Agreed, same here, but I think the radio for the 2015 thru 2017 is a different radio (as they are not compatible with later Fit models).

 

You could think it that way, that the audio unit is a computer located in place, which time to time may be very hot. Therefore a cooling fan is needed.

 

In my '18 sport, the fan stays on for several seconds after the car is turned off. Also, if I turn the car off but leave the headlights on, the fan will continue to spin, for some reason, until the lights are turned off.

 

I have the same issue on my 2015 EX. The fan must be temperature sensitive as I don’t notice it when it’s cold. After the car interior heats up and the head unit is heat soaked it’s very apparent.
I did report it while the car was in warranty but of course Honda Service was not able to reproduce it. (I really should stop calling it Service)

 

Sorry, but I don't fully understand what would have been the reason for a warranty claim? There is fan in the audio unit and it runs when cooling is needed.

 

When I first got the car the fan was not noisy. For about two years it was a silent fan. You could hear the airflow if you listened carefully but not the bearings in the fan motor. After about two years the bearings started to make a noise which changes or goes away for a few seconds if you knock on the head unit. I've seen this problem before on computer fans. I'm waiting for the fan to either get louder or for it to fail completely before getting into the dash to do something about it.
Does everyone hear this fan at low volumes when warm?

 

On my 2018, I hear it only when the engine is off, the head unit is on, and no music is playing. Having been in I.T. for 20+ years, I am very familiar with the bad bearing sound you are describing. While the fan on mine is audible when everything else is off, mine is certainly not making the tell tale dying fan noise you're describing.

 

As technology has progressed and aftermarket headunits have become more and more advanced, i think there should be an aftermarket head unit you can upgrade to.