humming noise

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Mar 16, 2021
I recently took my ford EV to the ford dealership because there is a humming noise coming from the front dash. i can't pin point exactly where. So they said it was the compressor and replaced that. $2000 later it is still making this noise. I don't know enough about this car to know what is under the hood. I don't even know if the compressor needed to be replace! Anyone have this issue? Thanks
I have noticed a fan noise coming from the APIM or the electronics in that area. Behind the navigation screen. Most likely what I am hearing is a circuit board fan, to keep cpus and other types of computer chips cool. It is fairly quiet.
Not a problem unless it is quite prevalent or offensively noisy.

I am sorry that your dealer is a crook. The A/C compressor makes a noticeable whine, however that is hard to hear in the cabin. Outside at the front of the vehicle it is easier to hear. And the whine is normal. If the compressor is going to fail, it will probably set a DTC code beforehand.

Listen for yourself, turn on the A/C, set the fan speed to lowest, get out of the car and stand at the front and listen. It will probably have a slowly increasing pitch. Turn off the A/C and stand in front of the car again, the whine will probably have a slow decreasing pitch.
Great!!!! I should have said no to the fix because I did open the hood to see if I could hear the humming noise outside the car. BUT I didnt have the car running or the a/c I expected more from the dealership! So if anything else is wrong I should get a code? They wrote in their notes I need a new cooling fan motor! Thanks for your help!!!!
Yes, if just about anything goes wrong with the FFE, there is a DTC code created. However, you are not able to retrieve these codes with a standard OBDII reader, you need an interface that can handle High Speed and Medium Speed CAN signals. You will also need a laptop with Forscan installed. I am quite happy with my OBDLink EX USB interface. Right now it is $50 at amazon. Some people prefer other interfaces, but they do not have automatic HS and MS CAN switching. You must manually flip a switch. Be wary of any interface that is less than $20 as there are many unreliable Chinese clones. To read codes, you can use the free version of Forscan. To do testing and changing parameters, you need to get a Forscan license. I think they are about $10 per year.

There is another way to see DTC codes, however I am not for certain if that method displays all codes. Read about Engineering Test Mode here:

Once you see the DTC codes, you can either use Google or the FFE service manual for more information. Get the service manual here:

I would not trust that dealer anymore. They are jerks. $2000 to replace an A/C compressor is too much, and it probably wasn't necessary. When they did that job, did they also replace the desiccant bag and flush the system? If there truly was a problem with the old compressor, they better have. You most likely do not need a fan replaced.
paperwork says that they did. They also did DTC scans and no DTCs were present. They recommended the a/c compressor cause they felt that was where the noise was coming from. When they replaced it the noise was no longer there! The noise im hearing is still there!!! I was just reading the paperwork they gave me. I should have just said no. Do you happen to know how much battery these car lose per year? whats normal and not? I'm in AZ and I know the heat is brutal on these cars. My car would charge up to 165 last year before summer and now I'm at 140.
sorry that is what my battery would charge to 165. that was full for my car. after this past summer it only charges to 140 at the most. Is it normal to lose that much? does that make sense? also that humming is more like a buzzing sound. It has gotten louder and seems to come from the push button ignition.
I am guessing that is 165 kilometers range? A 2017, 2018 should get that range in mild weather. In slightly warmer weather, the range will increase, but any use of the A/C will quickly negate that. Cooler weather and use of the heater could bring the range down to 140.

There are some basic means of determining battery degradation, but i prefer to use Forscan. Charge the battery up to 100% and then use Forscan to display the estimated battery capacity. At best, my 2017 seems to max at 29 kwh.

Sometimes i hear a buzzing noise come from the center display, this caused by the voltage inverter to drive the fluorescent lamps of the LCD panel. sometimes it is noisy, sometimes it is silent.
Well that noise is getting louder and it’s everyday. So idk what I should do. Don’t know who to take it to if the dealership is gonna screw me over! I really don’t use the a/c even when it’s hot cause I know it drops it down quite a bit. Thanks for helping me out. I love my car but I’m still learning things about it!
I dont know where you are located, but a good independent shop that specializes in hybrids might be better than the dealer. At least they would be knowledgeable of electric drivetrains.
Heima said:
Yes, if just about anything goes wrong with the FFE, there is a DTC code created.

They're absolutely worth looking for, but know that they are by no means guaranteed.

My battery cooling issue has caused the pack to heat to the point of a "stop now safely" warning without throwing a code.
Here's some good info on a buzzing noise coming from the dash (link below). This small fan is right below the stop/start button. My 2017 FFE had this exact problem as in the linked post and I fixed it according to their recommendation. This appears to be a common Focus problem, not just an FFE problem. But maybe we hear it more than other Focus owners because our EVs are so quiet.

I was able to raise the steering wheel, reach behind the knee bolster panel, grab this sensor and pull it out in the open. Even after I did that, it was still buzzing, so it seemed that the problem was in the part, not due to it being loose in its attachment. Then I disassembled it by prying up the 6 clips that hold it together, and cleaned out all the dust. The fan pulls off of the axle easily and I cleaned all the dust there too.

When I reassembled the fan, it was quiet. I wrapped some soft velcro tape around it (leaving the vent holes open) to muffle the sound in case it happens again. Then I stuck it back on the panel where I found it.
I always thought that was humming from the touchscreen backlight inverter. Guess I will have to check it out, cause it sure bugs me.
Thank you Petehouk!

Well whaddya know, it is a little fan back there making the noise. I pulled it out and it was filthy dirty. Greasy lint all over the impeller, and very dusty. Took it apart and cleaned it up with q-tip swabs, alcohol, and compressed air. There is a little thermistor and humidity sensor on the internal circuit board. But after installing, it still made the noise. So at least I know the cause of the noise, but I wonder if a new part would be just as noisy? The fan motor design reminded me of a stepper motor, but spinning the impeller did not have a cogging feeling.

Here it is at Rock Auto. $46

Ebay $25 pre-owned Probably no better than the one in your car right now.

China knock-off, if you would believe it, at Amazon $30 The original equipment seems cheaply made, so this knock off is probably total thit.

To Remove
1. Raise the steering wheel to the highest position.
2. Reach your left hand into the opening under the steering column, and move your fingers to the right, towards the nickel-sized round vent. If you have big hands, you may not be able to do this.
3. The fan is press fit to the backside of the lower instrument panel trim at that vent. Just move the fan towards the front of the car to pull it out of the trim.
4 Bring the fan out through the opening under the steering column.
5. Disconnect the harness from the fan connector, by moving the tab on the connector away from the harness.
Installation is the reverse.