We recently were driving with the vent fans blowing on high (face vents selected) when all of a sudden the fan noise changed to a very loud low pitched "howl" and at the same time air stopped coming out of the panel vents (or barely trickled out at full fan speed)... Now no matter which vents I select with the knob- no air will come out of the selected vents and the loud low howl fan sound stays the same.. My instinct tells me a duct somewhere detached- maybe close to the point at which air gets routed. Anyone ever have anything like this happen? I'm looking for some easy places to start or targets to head for before I start diggin behind the dash willy nilly.

 

Does it work on heat, or just on cold?

If you open the hood and feel the left AC line, is it cold to the touch?

This happened to me awhile back. I ended up having to change the resistor and blower motor to fix the issue. Apparently the blower motor that comes with the FIT is known to fail.

If you turn off the AC completely and then wait a few minutes, it should come back on temporarily.

 

Heat and cold (air conditioner) both work 100%. It is just that air isn't pushed out of any vent (on any temp/fan setting). If I put my hand up against any vent in any mode I can feel hot or cold air as appropriate based on heat/AC setting, but next to zero actual blowing force. I think the blower motor is functioning normally since I can hear a loud low "woosh" increase/decrease with fan speed setting changes.

 

check the filter. Maybe some critter in there.

 

Id try replacing your cabin air filter, then.

Does it work when you first startup the car?

 

That sounds like the blower fan might have been clogged by something or detached from the motor. Also possible the motor disconnected from the housing or is broken. Once you get to the motor this is not so hard to assess.

You might remove the cabin air filter first as it is easy but I don't think that is your issue.

I don't think it is the blower fan resistor, unless the fan stops working on certain "steps" or completely stops working.

 

Is it possible that a plastic bag got sucked in and is blocking the fan or the filter?

 

Hold on! When I started the car today it worked fine!! Yesterday when it seemed to have failed I tried shutting off the car for 20 minutes and restarting but it didn't solve the problem. Apparently letting it sit all night did... I guess this means if I run the blower for an extended period this may recur..? This seems really strange.

 

Eventually electric motors get intermittent. That could be from damage (water, dust, foreign objects). Bearings can wear out. Brushes/contact points can wear out.

On other cars with blower fans failing, gently kicking the motor housing could get it to work, sometimes.

If you run a failing blower motor (e.g. which is noisy or blocked) that may draw a lot of current and heat up. To prevent electrical fires, the blower resistor pack typically has a fuse that should blow. Then you probably have to replace both the fan and the resistor pack.

On a few different brand cars, I have cleaned and re-lubricated fan motors. And rebuilt blown resistor packs as the packs are so expensive (replacing $0.10 thermal resistors which are fuse protection). I don't know what Honda uses so can't help more.

 

As I've said before oh, this happened to me a while back. It only works in bursts you have to turn off the AC completely for a few minutes, the longer the better, and then start it up again and should work momentarily. It has to do with the blower motor not getting enough voltage, and will eventually go out entirely on you.

In my situation, I just went ahead and replaced the resistor first only for the blower motor to fail again in another month. In essence, your blower motor and resistor both need to be replaced.

Put my new stuff in a few weeks ago and works perfectly fine.