2006 Envoy SLT air suddenly stopped blowing from vents

I believe, on the Envoy, there are three small motors that run the Vent doors that direct the air flow. Obviously one is not working properly

The blend door or its actuator in the rear HVAC unit (behind panel on passenger side cargo area) is either stuck or defective.

Could be a blown fuse. That's most likely. If not, it may be the switch for the front.

Sounds like defrost door on heater box is not work You need to get under dash and check controls on the box. Good luck

{: ) The popping sound you heard is caused by the sudden movement of an HVAC door, most probably coming from the recirculation door actuator (right dashboard area) or the mode actuator( mid dashboard area). The fan outputs could be normally working, but is being muffled by the incorrect positioning of the HVAC doors, giving an impression that there is fault in the blower controls. In other words, your vehicle is having an air distribution issue.
If there's no conflict in your climate settings, then the trouble may be in the HVAC doors binding or broken, or the actuators faulty or sticking. In both cases, servicing may involve removal of the dashboard to access these HVAC components.

you have a vacuum loss to the ac control head, the motors that divert air are vacuum operated, if you loose vacuum the system goes to defrost for safety reasons, the vacuum comes from the engine, then goes o a plastic vacuum tank under the hook start there, it is a 3/16 id hose.

Most of the time the problem is that the upper hose that feeds the air to the vents has fallen off and is blowing air somewhere else.

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.

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

You most likely have a bad mode actuator. http://forums.trailvoy.com/showthread.php?t=40235