Humming sound when is fully charged

Hi,

I was wondering if any of you had a experience when focus is fully charged, car itself makes a loud humming sound. I recorded it and sent it to the service and are waiting for a reply from them.

This happened once a while (it's been about a month since I had Focus) but now it happens every other day.

Worried...

Thanks!!

Sorry, here comes a few questions to better understand your situation...

I'm guessing this is happening when the car is done charging but still plugged in, correct?

Are you using a 240V EVSE or the or the included 120V unit? If using a 240V EVSE, which brand?

Has the car thrown any error codes or showed any unusual warnings or error messages in the screen left of the steering wheel upon starting?

Have you tried using the 120V to see if it behaves the same?

Thank you Fluke for the reply!

I am using 120V from the garage and I didn't see any error codes.

It makes a really loud "mmmmmmmmm" sound and would turn off if I unplug the car.

I was wondering if anyone had a same experience.

Thanks!

Gina

I have not experienced this issue, but if the sound stops when the car is not plugged in the charging system components are initial suspects. Are you able to tell if the noise is coming from the front or rear of the car?

Gina, I'm new to this forum but hope to learn a lot about the Focus Electric from the people here. Living and working in the auto industry in SE Michigan, and knowing several of the Ford engineers on the program as well as some of their suppliers, I've learned a fair amount about the "inner workings" of the Focus Electric. However I'm not professing to be an expert.

One thing I do know about the Focus is that the battery cooling system may potentially run any time the charge cord is connected. As long as the vehicle is plugged in (whether its charging or not), the thermal system will monitor the battery temperature. So even after charging is complete, the cooling pumps (there are three of them) and AC compressor can come on and off to keep the battery at the desired temperature. If the air temperature is very high where your vehicle is parked (such as in a closed garage) while on the charge cord, the pump(s) and compressor will come on and off to keep the battery at its required temperature even if it has stopped charging. This may be what you're hearing. The pumps and compressor are all located beneath the hood.

Also, in cold temperatures with the vehicle plugged in, the pumps may run (and the coolant system heaters turned on) to warm up the coolant. So may may hear the pump(s) run in cold weather too if it's plugged in.


You may very well be experiencing a normal condition. However if you feel there truly may be an issue, obviously it's time to bring your Focus in to your dealer so they can check it out for you and give you peace of mind.

Thank you GtBeMe and Fluke.

Your replies were very helpful!!!

Can you post the sound here? I think others are right in that its the battery cooling system or the car energizing the power braking / power steering system due to the proximity of the key. Do you have the key nearby or are you unlocking/opening car doors when you hear this?

I hope I know how to upload sound. Sorry!

But I took the car to the service and learned, yes! it is the cooling fan sound.

Thanks for the help all!!

Actually, I pretty fond of the random noises that come out of my FFE. I'll be walking by it in the garage long after I've driven in it and it will make a hum or a clicking noise or something. It kinda makes the car seem like its awake and biding its time waiting for the next drive.

I agree with GtBeMe. My FFE does this during charging with the 240V supply, directly after charging and after 2 banzi runs up to top speed back to back. Most of the noise is the radiator fan running, you can open the hood and see it running and feel the hoses running to the radiator, they are warm and vibrating. I expect a lot of that to go away when the garage cools off after summer. My garage temp has been at 99 degrees in the evenings when the FFE is charging. On the top speed runs, all I did was stop outside, within a minute of the run and the fan was running.