Air not blowing from top vent of 2002 gmc envoy

SOURCE: Dash vents will not blow air

It may be the mode actuator. Have you heard any clicking or other strange noise ? Under the drivers rear seat, in a plastic box is a fuse panel. Remove the two retainers, and the cover. Remove the HVAC or A/C fuse for a minute or two. Reinstall the fuse and this will make the A/C system relearn. Whwn you put the fuses back do not touch the A/C controls. Start the truck and leave it run for two or three minutes. Then try to change the vent from floor to vent and defrost. If this does not work you will need a mode motor. Good Luck

SOURCE: 2004 GMC Envoy; Very little air flow from FRONT PANEL

Try replacing the cabin air filter.

SOURCE: Dash vents will not blow air. Defroster and floor vents blow fine.

Is it a new vehicle? I had a new vehicle that had the same problem. Answer was that the holes weren't punched out of the vent.

SOURCE: air conditioner not working properly

I have just ordered the part to fix this. It is the A/C vacuum actuator (not sure why they call it a vacuum actuator because it is an electric actuator). It is under the dash on the driver's side close to the radio. There are two in the same area. It is the one closest to the floor. You can verify by taking it out (pull out duct that runs from center of vehicle to the outside to get better access), and actuating the vent by hand with the blower on to see if you now get air out the middle vents.

The part number is 1573596 from Rock Auto on the net. It cost $40.79.

SOURCE: front vents don't want to blow air - new battery

Changing the blower motor resistor will solve the problem of the unchanging fan speeds and the blower motor having power when the ignition is turned to the off position. Beware that there are three different kinds of blower motor resistors. There is a manual, automatic, and a digital that in appearance is greatly different from the first two. The blower motor resistor is located on the passenger side below and behind the glove box. The kick-plate under the glove box will need to be removed by two screws and wha-la, behold is the motor and resistor.