the middle vents only supply air from the ac unit using a separate in dash fan. the floor and defrost vents come only from the heater
Does air come out at defrost vents? Defrost is the default position. Check for a vacuum leak either under the hood or under the dash Check the operation of the vacuum actuated motors under the dash Check the operation of the selector switch
I just had that problem with my 99 Monte Carlo. When I accelerated or went uphill No air would come out of the dash vents. Problem was a Vacuum hose. Cost about $40 to fix.
The flap that directs sir to the selected vents is jammed or broken...or the switch that controls it is.
well when mine did it was a vacum line but the dash did have to come off
Hey Brad==That is where it is suppoaed to come from. Incidentally, what kind of car do you have?? Goodluck, Joe
some thing is probley cloging the vents take it appart and ckeck.
Check your ductwork under the dash it sounds like it has come loose not a big deal to do.
Check vacuum hoses and diaphrams under dash and at firewall
Heat and steam coming from the dash and air vents after replacing the water pump means that a hose is hooked up backwards in the new installation. The heater is actually taking on water when it is supposed to only take on hot air.
prior out with a flat screw driver
Yes, gnats can come out of dirty air vents. Gnats can actually come from anywhere. They are very pesky creatures.