the blower switch located behind blower motor is shot or burned up. it cost me about $30 dollars at auto zone and 5 minutes to replace. you out.
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.
Clogged cabin filter
i had same prob w my 2006 ls It still worked on certain settings cause the module didn't completely go yet but it was on its way out it cost me 150 ish for the part and I had someone install. does yours work on any setting 1-5 ?
Because there is a known issue with the brake lamps on the 2003 Trailblazer. I own a 2003 Trailblazer and had to take it in for service on a recall due to the issue. Take it to your Chevy dealer and have them check the VIN to see if the recall was ever done.
if it doesn't heat your heater core is most likely clogged and if it doesn't blow at all then the blower is messed up.
Replace the high speed relay.
I recently had to change mine...about a $25 fix. Kind of a pain to do but not bad. The blow motor resistor is behind the glove box. well i have a 2003 Chevy trailblazer ext but i assume they are the same. just empty the glove box...and it kind of forward and exposes the parts behind it. mine was to the left. hope this helps!
You may have a faulty switch that controls the speeds on the a/c blower fan.
Low on coolant. Bad thermostat. Plugged heater core. Temp blend door inop.
Blower circuit board is shot
Take it to a repair shop because the clock spring below the airbag in the steering wheel is probably defective.