Ian Park

-The regular creaking sound was heard when I turned on the heater 2 weeks ago when it was turned off suddenly. (This cracking sound was heard every winter but Normally this noise was gone after few mins driving.)
-I turned off my engine then I started my car then I turned on the heater, Luckily Heater did work but the wind is blowing very weakly and also blower motor has been made noise since this time when I turn on the heater(A/C as well)
-Wind strength controller is working but 1level~3level is blowing super weak.
the full strength of the wind is like 3 level wind strength.
-so I bought a new blower motor(OEM) then replaced but nothing better than before. A blower motor is still making noise and the heater is blowing weak(but the wind is enough hot).
oh and also I think I smelled some burning smell when it's happened and both sides of front interior lightning were dead (I turned on it for checking my blower motor at night) I am not sure those things help to figure out a factor of this problem.

I would bring my car to the dealership next month but I would like to listen to opinions from you guys first and how much do you expect to repair it?

Thank you so much to read my thread and sorry for my bad English!

ezone

Check condition of cabin filter?

Ian Park

Yes, I did!
It's petty clean and even I check my heater after taking off the cabin filter but nothing changed

Thank you

Ian Park

I am assuming busted resistor but I couldn't check it because some plastic guard is blocking and I don't know how to separate it...

is there anyone who knows how to separate this plastic guard?

ezone

Don't assume. Test, don't guess.

There isn't really a resistor per se, because it's not a 4 speed fan control. It's an electronic unit (Honda calls it the power transistor) that allows nearly infinite speed control.
Every power transistor failure I've ever seen in a Civic caused the fan motor to not run at all, so if the fan motor works at all I would not suspect that failed.. (Again: Test, don't guess)


Does the fan motor sound like it's spinning full speed? Is it rotating the correct direction?
Does air blow out in the correct locations with each selection of the control panel?
If you unplug the power transistor and connect its two largest wires together, that should cause the fan motor to run at maximum speed.



You mean the panel under the dash that hides the important stuff? Pull the rear edge straight down.

Ian Park

I found an exact same case in another civic forum

https://www.9thgencivic.com/forum/me...e-control.html

the noise from this video is exactly the same with the noise my blower motor makes!

I have a 2013 Civic Coupe EX-L Navi with the Auto Climate Control. I never use the Auto function, just adjust the fan speed. I bought the car in July 2013 and a few weeks later the HVAC fan started making a buzzing or ticking noise. The pitch and frequency would change as you adjust the fan speed. The amount of air coming from the vents did not seem as powerful as my 7th Gen Accord that I previously owned. I took the car back to Honda and they heard the noise and replaced the blower fan (79311-TR0-A01).

It was quiet for a few weeks, then the same noise returned. I couldn't get the car in right away, so I continued to drive it. The AC always blew cold air, but the fan was noisy. As the weeks went by, the fan began to fail. At the highest setting, which is 7 indicator bars on the display, there was not much air coming from the vents. Sometimes it happened immediately, other times it took about 30 minutes of driving before the fan would begin to fail. It got so bad, there was barely any air coming out of the vents at the highest speed setting.

I took it back to Honda and the fan was barely spinning the moment I started the car. I left the engine running with the AC on and had the service advisor sit in the car to confirm the problem. He confirmed it was not normal operation. Since replacing the blower motor the first time did not solve the problem, they did further research and discovered the fault in the system. The blower resistor/transistor (79330-TS8-A02) was burning out the blower fan. Honda replaced the blower fan and the resistor/transistor to fix the problem. So far, that appears to have fixed the problem. The blower fan blows better than it did when I first bought the car, and it is quiet without any noisebutair coming through the vents. I think the resistor/transistor was bad from the very beginning and it burned out the fan, twice.

Here are the service bulletins referenced on my warranty repair invoice:
Blower Motor: 09-097: HVAC Blower motor works only on high speed.
Blower Motor: 11-008: A/C - Blower motor is noisy/reduced blower speed.
Resistor/Transistor: 87-003 - Could not find a TSB on the internet for this one.

I was only able to find a link for the TSB 09-097, which was for the 2009 Fit. The cause was excessive current draw from the blower motor causing the blower resistor to fail.Repair was to replace the blower fan and blower resistor. I found a paid link for 11-008, which had the title "Blower motor is noisy/reduced blower speed." I could not find a website with the TSB to view it. I could not find any listing for 87-003.

So if you are experiencing similar problems with your Civic's HVAC system, the resistor/transistor, which controls the fan speed, might be the problem. Below is a YouTube link with a video demonstrating the problem with the blower fan. Make sure your speakers are on because it is the sound you want to hear, not the visual to see. The fan was on 7 the entire time and you will hear the slow buzzing noise as the fan was barely spinning. You will hear the fan try to spin faster, but then slow down again. The fan will continue to fluctuate while the car idles. At the end of the video, I turned off the HVAC system and turned it back on so you can hear how loud the noise was in a quiet car.

You Tube

I hope this helps others that experienced the same problem.

What do you think about it?

-Does the fan motor sound like it's spinning full speed? Is it rotating the correct direction?
-It's blowing weakly! not strong like before! and yes it seems it is rotating the correct direction(if not it will not blow any wind i guess)
-Does air blow out in the correct locations with each selection of the control panel?
-yeah, it does!
-If you unplug the power transistor and connect its two largest wires together, that should cause the fan motor to run at maximum speed.
- I can not get it how could I put two largest wires together? Can I just unplug the power transistor and test it?


and this is the photo of that plate which covers power transistor. I have no idea how to separate it

Ian Park

If my problem is the same with that case. It makes sense why I smelled something burning.. I guess this broken transistor burned my blower motor...
I should test it to buy a new transistor.. hm

ezone

I reviewed service bulletins (for USA) and found none addressing a blower issue for 2012 Civic.
Remove the glovebox from dash
remove screws (3 ?) for the small plastic duct, remove duct.
Now you should be able to reach the power transistor and its connector.

Yes

Check maximum fan motor speed:
If this makes the fan run much faster than it had been, then I'd suspect the transistor.

Ian Park

Thank you so much for your advice!! I will try to test it ..it seems like the most difficult part is removing plastic duck.

ezone

I have fabricated jumper wires with correct terminals and heavy duty wire for this sort of check.

Ian Park

Is there anyone who knows how to remove that plastic ducts ?? video or photo? it doesn't come out for god sake even after removing 3 screws

Ian Park

I have a question, Sir! Even though it makes noise and blows air weakly anyway it is working so I think there is no problem with a blown fuse or a blown wire thing.
Am I correct?

ezone

Fan related fuse blown would cause the fan motor to not work at all.
Everything else to do with the circuits could contain variables that create not so simple answers.

Example: Unwanted excessive resistance in a circuit (or wire) could cause reduced motor speed, same as what a blower resistor would do to the motor, right?

Ian Park

I got it! I am going to check the power transistor tomorrow and I will keep updating what's going on with this problem.
Thank you so much!!

Ian Park

Please check it out!
This is mine

and I found this video on youtube



As you see mine is weaker than the blower motor in another video when it's maximum blow level...
I couldn't test a power translator because of that plastics I think I should remove passenger side dash with the glove box. rather than removing those plastic things (I removed three screws which I can see but it doesn't come out easily it's like this things are saying that don't touch me)