2004 trailblazer no air coming out of vents only out of defroster and AC compresser won't stay on

s_pra_army

• 37 Answers
• Posted on May 10, 2009

SOURCE: hot air comes out of defrost vent at top dash and cold air out of

Hey, what setting is your A/C on Max AC? AC? Cycling air in vehicle or taking it from outside

The car icon on the right in this image is what I'm referring to when I say cycling air in vehicle.


Also, do you ever have cold air blowing? on any setting or any speed? if not, find your A/C fan, it is smaller the the engine cooling fan, sometimes there are 2 fans together. The AC fan should be located at the front of the vehicle and is usually electrically powered.

Also try to find your compressor, looks something like this:


is it running? is one pipe hot and one cold? (the pipes I am referring to are inlet and outlet pipes of the A/C compressor unit.)

Hope this helps, keep me posted

Bill

• 424 Answers
• Posted on Jun 08, 2009

SOURCE: Problem with air not coming out of vents.

Check for a vacum leak from the engine to the a/c.The color of the hose is black. Also check if the heater control valve hose is unplugged. If you have vacuum the it sounds like the door for the vent/floor/defrost is broken.

SOURCE: My AC air registers only have air coming out of the defrost ducts

In every car, there are fins or flaps inside the dash that rotate that distributes the air flow from the blower to the desired opening, ie defrost, floor etc... This flap is controlled by a linkage which is connected to the selector switch. It may be the linkage is no longer connected, or the fins inside the dash are stuck. If the selector switch moves freely with little or no resistence its possible the linkage is no longer connected, otherwise the flaps need to be physically looked at.

SOURCE: 2003 Trailblazer No air from front face vents

first check to see if you have power going to the actuators when you switch the switch to it location if no power replace controller if you have power and no movement from actuators replace actuator. if actuators move remove hvac box and check for broken blend doors.