2006+ Honda Civic Forum banner

Fans are blowing but no air....

AC/Heater 
16K views 19 replies 9 participants last post by  Robbie 
#1 ·
Hi all,

One is having a little issue here. This has come and gone over the last year, it just randomly happens then a few days later will work fine.

Essentially I can clearly hear the fan is blowing away ( I take it the fan is near the glove box... ) but I get basically no airflow out of any of the vents.

If I cycle the modes there is no change of air flow. What one is assuming is that there is some mechanism for redirecting airflow and that that is getting stuck.

Now I am perfectly happy to investigate this myself but tearing apart the inside of the cabin is not something I have every attempted on my Civic so some guidance on what to look for or possible simpler fixes would be appreciated.

Regards

Ed
 
#2 ·
Sounds like a connecting pipe has come off somewhere, possibly in the passenger footwell, also check the pollen filter isnt blocked and is fitted correctly.
 
#5 ·
I took the dash out of my car in an attempt to rectify the same fault. Just to check - if you leave the vehicle for 10 minutes it should 'reset' itself. But ign off and on will not make a difference. It is the mode control motor mechanism somehow. However having had it all out and made a thorough examination of the linkages and associated mountings and motor itself, its physically impossible for the mode control motor, or more correctly the flaps it controls to get into a position where there is no airflow. However . . . the problem persists on my vehicle as well. I thought I had found the issue, because there was a very small piece of debris in one of the channels on the control wheel into which the flap control linkages engage (this is attached the rotating control motor spindle). Alas seems I was wrong. I am reluctant to give up yet another two days to have the dash in and out again. It's a complicated operation and it took me ages to find a dodgy SRS connector after I had replaced it all the first time. My cars getting a bit old for too much brutal maintenance.
 
#6 ·
Thanks for your input.

It is intermittent, usually if it decides not to work it stays like that for a day or two then it works again. Often when it gets cold.
I watched a video of another Honda model and the Mode Motor goes into a resting position when the air con was shut down and returned when it was activated. This is what made me consider a fault with it.
Was there some form of grease on the unit that may cease up in the cold ?
Do we know of any relay / fuse that could cause such an isolated bug ?
Is it a complete dash removal job to get the area ?

Ed
 
#7 ·
There is some red grease on the wheel which the position motor rotates. Everything is plastic in there though and to be honest, well designed, smooth operating etc. If you remove the drivers under dash panel and use a torch you can see where the position motor is, it's about level with the radio. So very high up. Even if you have the hands of a five year old, I just wasn't convinced I could ever replace it once it was out. It can't be linkage issue it has to be some logic error with programming in the HVAC unit. ... ? right ?

So yes sadly a dash out job. You will need a friend to help get it out. Both the seats out first, which involves disconnecting the SRS, which is battery off for 15 mins. Top tip though, with the steering column, just undo the top bolts which hold the entire unit to the dash and then disconnect it at the sliding joint near the clutch. (after first doing all the electricals of course.) Saves about an hour of needless steering wheel dismantling. Then TAPE the steering wheel to the housing so it """does not rotate""" otherwise you will break the connecting wire between the steering wheel and the car.
 
#10 ·
Well I have the same issue. Short journeys and the heater operates fine, but I did a 300 mile round trip yesterday and all the heater flaps closed with no air coming out. Can hear the fan spinning at max when the temperature control is up to 'high", but no air comes out any of the vents.

Working fine this morning.

Going to replace the actuator in the first instance, but as it sometimes works normally, I'm thinking it's the control rather than the actuator. Actuator is cheap though and fairly easy to access.

Anyone know what controls the actuators please? Is it a separate HVAC module or all integrated into something else.
 
#11 ·
I have another long trip tomorrow. I've replaced the heater control unit with one from a breaker and we'll see if that solves it. I have a spare flap control motor to try if this doesn't work. Just replacing one thing at a time to try and pinpoint the fault.

Will report back for anyone else who may have the same issue.
 
#12 ·
Well it didn't work as the vent flaps all closed after an hour or so. The difference this time was that I knew about the diagnostic mode from the wiki.

From this diagnostic mode, the vents were 0% open and the cabin temperature sensor was telling the climate control system that the interior temperature was 32C. If it really was that warm inside the car I think I'd have had my shorts and t shirt on! Favourite for replacement is the cabin sensor then. Probably breaking down after being powered up for a while.
 
#13 ·
Did the same journey this weekend and the fault didn't occur. Difference was the ambient temperature was higher and at times I actually had cool air blowing through the vents as the sun was warming the interior.

Regardless, I have changed the interior temperature sensor (or at least the sensor thats in the heater box) and will report back on any developments.
 
#14 ·
Replying to myself but if it helps somebody in future, all is good.

I now believe the fix is incredibly simple and best of all, free.

As I mentioned above, I replaced the sensor in the heater box and as may be apparent, I wasn't 100% sure I had replaced the correct sensor. Actually I was pretty sure I hadn't. So I ordered a replacement trim panel for below the rev counter from ebay with the cabin temperature sensor still attached - so I could replace the correct cabin temperature sensor.

It duly turned up and I immediately noticed a difference as the little grill slats were far more open than the one fitted to my car and the thermistor was visible through the grill. The grill piece on my car was pretty blocked with fur and other detritus. So I figured no air was passing over the thermistor and it would eventually report an incorrect cabin temperature, causing the heating to close down.

So I have cleaned out my grill with a toothbrush and it's all presently behaving. As always with intermittent faults it's difficult to be 100% certain until a while has elapsed, but I'm pretty sure it's working ok now.

So when cleaning inside the car, give the little grill behind the indicicator stalk a quick blast from the Hoover. Don't be a plank like me and replace half the heating control system. :D
 
#18 ·
Replying to myself but if it helps somebody in future, all is good.

I now believe the fix is incredibly simple and best of all, free.

As I mentioned above, I replaced the sensor in the heater box and as may be apparent, I wasn't 100% sure I had replaced the correct sensor. Actually I was pretty sure I hadn't. So I ordered a replacement trim panel for below the rev counter from ebay with the cabin temperature sensor still attached - so I could replace the correct cabin temperature sensor.

It duly turned up and I immediately noticed a difference as the little grill slats were far more open than the one fitted to my car and the thermistor was visible through the grill. The grill piece on my car was pretty blocked with fur and other detritus. So I figured no air was passing over the thermistor and it would eventually report an incorrect cabin temperature, causing the heating to close down.

So I have cleaned out my grill with a toothbrush and it's all presently behaving. As always with intermittent faults it's difficult to be 100% certain until a while has elapsed, but I'm pretty sure it's working ok now.

So when cleaning inside the car, give the little grill behind the indicicator stalk a quick blast from the Hoover. Don't be a plank like me and replace half the heating control system. :D
Do you mean the girl in front of the car or in the cabin of the car? I have the exact same issue as you.
 
#16 ·
Had exactly the same problem fan running but no air coming from anywhere!
This happened iin the winter resulting in a cold car and in summer resulting in a hot car but only after long journeys, about two hours?
Vent seems clear so might replace the thermister, do you know what the spec is? don't worry if not i'll take the old one out and measure the resistance as it seems to be working at the moment!
thanks
Mike
 
#17 ·
What cabin temperature is the thermistor reporting when it's in fault condition? Put it in diagnostic mode as described in the wiki when the fault occurs. Not that easy with an intermittent fault admittedly.

No idea on the specs I'm afraid, I replaced it with one from ebay. At least it's really easy to get at. It's the one behind the grill above the steering wheel and the trim just pulls off.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top