Probably the mode door actuator. We have instructions on the replacement procedure on our enthusiasts forum at www.trailvoy.com
If the air vents of the Chevy trailblazer 2004 are not blowing air, have the fuel pump checked.
The air of your Chevy trailblazer 2004 blow out of the front vents when the air conditioner is on because the air condition is faulty and it needs repair.
The vents are opened and closed by vacuum. There should be a vacuum line running from the engine to the inside of the Trailblazer. That line is broken somewhere and it is not sending vacuum to the switch. That will cause it to blow to the top of the dash (defroster) and to the bottom (floor.) Find that line trace it back and splice a new line in where it is broken. That should fix the problem.
Could be the mode door actuator. For more info visit our enthusiasts forum at www.trailvoy.com
2003 crown vic air conditioning vent dont blow
if the fan motor isn't working, the fan motor has likely got a loose connection of some sort. if the fan does work but the reguler vents don't you might have something blocking them.
Chances are that this is a PICNIS situation- Problem In Chair Not In System- make sure you have the button that makes it blow out of both vents... it looks like a little person sitting and has an arrow towards his head and an arrow towards his feet. If the problem still exists then I would consider two things- car is broken, or you're forgetting physics- Hot air rises, cold air falls... maybe the fan system isn't strong enough to force the hot air down to the lower vents along with the top vents... the bottom line is that you shouldn't be doing both... I would just set it so its only trying to blow hot air out of the floor vents- its a much more effecient way to heat the entire car.
Bad selector? vacuum leak at engine or vacuum motors under dash
why dont bottom vent doors not open on 2001 gmcsonoma
Either the a/c system is low on freon or the evaporator has an internal restriction....
The blend door actuator may not be working.
The flap that directs sir to the selected vents is jammed or broken...or the switch that controls it is.