kupuna

'04 Civic LX Coupe. The only thing not working is whatever diverts air to the front window "defrosting" vents. My mechanic says he needs three hours of labor plus a new actuator.
Since all the other vent settings and the fan are working, I'm puzzled that this is such a major thing. Could the one vent "flap" just be sticking?
I'm too old (really) to crawl under the dash, but could I get at anything if I took out the glove box? Is this really a big deal to get at the actuator and/or flap?
If anyone has experienced this under-dash hassle, I'd really like to know if it will require a near $400 repair bill. Anyone know where to find a diagram of the under-dash layout? Thanks a lot!

ezone

Mode control motor is accessed through the glovebox opening, but the PCM is supposed to be removed to make room to reach it.


The mode control motor is just a servo, with a series of contacts that act as a position sensor so the control unit knows where to stop the motor

It screws to the side of the heater housing.....and there are probably multiple levers/links that this servo moves as it operates......so there's the possibility of a failed servo that doesn't make full range, or possible issues with some of the linkage that opens and closes the flaps inside the housing, or who knows what might be discovered once someone gets in there to actually take it apart.

Maybe a pencil or lipstick fell into a vent and made its way to jam up a flap somewhere in the housing.