Hello All,

I have been reading through old posts, but have not come to any definite conclusions yet. I have the "computer climate control" on my 2000 blazer LT. My heat and ac work and I can change the temperature, but I cannot get the vents to change--currently air only comes out of the dash vents. When I turn the switch for the vents I can hear something moving behind the HVAC control, but the air keeps coming out of the dash.

I have checked the fuses and the vacuum lines. Does this sound like it may be the control unit itself?

Thanks,

Zach

 

Have you checked ALL the vacuum lines including the vacuum accumulator under the hood or in the DS fenderwell? The lines leading to & from it & under the dash?
Could also be the blend door that's broken or disconnected.

 

Yep...as stated above....likely the vacuum swith on the control panel. Take the panel out and check the vacuum connection it is probably leaking.
All the vents are controlled by vacuum motors or actuators. If the vacuum is not getting to it, it will not move.
Just be careful with those colored vacuum lines....you do not want to break any of them.

I think the switch is not too expensive to replace.