My 1992 Civic VX blows very weak air out of the vents. The AC is cold, the heat is hot, and the doors that switch air from floor to vents to defrost seem to work fine. It's just that even with the blower on full speed, air barely trickles out of the vents.

I've already replaced the blower motor. I thought the evaporator fins might be crudded up, but it blows just as weak with the heat on. It blows equally weak out of the floor and defrost vents.

I've pulled the blower motor back out to look up into that area and I see no debris.

I'm about to evac the AC and pull out the evaporator box to clean it out.

Any other ideas?

 

Check the vent damper flap control cable, sometimes they slip on the outer spring bracket holding the cable in place, under the lower dash or the slider control itself.

My del sol had mucho old leaves in the heater/cooling coil box you can't see it without parting the box though.

 

so all the levels 1-4 work and the fan gets consistently louder as you move the slider? if it sounds like the fan is working its *** off and nothing is coming out then i would agree you must have a blockage somewhere.

 

Also, if you're evacuating the A/C and opening up the evap --- maybe my POLLEN CABIN FILTER DIY will help to prevent future clogging!

 

Blower motor resistor... Check and/or replace it.