Hello, I'm hoping someone here will be able to help me with a problem I'm having with my 2002 civic's air ducts. Heres the deal, the car randomly quits blowing air out of the vents. A trickle of air can be felt when you select the vent. Blower works great in all speeds. I pulled the filters out and cleaned them and verified the blower was actually blowing. The motors that move the vent doors both seem to be moving and changing according to my selection. The problem has come and gone now a few times for no apparent reason. Is there another door in the ductwork that could be failing and causing blockage of most of the air? The fact that it comes and goes suggests its not a blockage of some kind. I'm lost and I'm hoping someone here has seen this before.

 

Next time it happens immediately pull over and do the HVAC self-diagnostic: https://honda-tech.com/forums/honda-civic-2001-2005-78/floor-heat-stopped-working-2864435/

Post back with the code.

 

Thanks for the lead. Ill let you know what I discover

 

I ran the test today because it started acting up again. The test ran but didn't flash any codes at the end. I was hoping this would give me a lead but no luck. Anyone have any ideas?

 

Weird.

When it stops blowing out of the vents, has the mode control motor switched positions? I'm just wondering if there is some sort of miscommunication going on between the HVAC panel and the mode control motor or something. Guessing, really.



Have you done any preliminary investigation with at least a screwdriver and a flashlight? It's a long shot, but...

 

I've torn the ductwork apart partially to look around and didn't see anything unusual. The mode control motor seems to be responding to inputs. Even when the air suddenly quits coming out of ductwork. Anyone ever heard of the plenum for the ac freezing up? I know it happens in homes when the system is low on refrigerant. Plenum turns into a block of ice. I'm trying to find a fuse I can pull that will ensure the ac doesn't run, in case it's staying on when it shoukdnt