If your vehicle has an in cab air filter, it may be plugged.
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.
Probably low on freon. Have the system tested for leaks, repair if necessary and recharge system.
If the air vents of the Chevy trailblazer 2004 are not blowing air, have the fuel pump checked.
air want blow out vents
No
how do you change the air condition controller in a 2004 chevy silverado
When you have the heater on, does it just blow any air at all? or no air?
I've got a better question, why is this question in the Chevy venture forum ?
Possible blown fuse
Check your anti-freeze levels
check heater fan to see if it is working.
Replace your cabin air filter.