Vent Problems??

Wow, do I have bad luck. One day after posting on here saying my Blazer is fixed and runs great...more issues.

K here goes... 95 Blazer LT, 4.3L V6

For some reason I have no air coming out of the vents on my dash. I turn it to vent and air comes out the top of the dash by the windshield(like it is on defrost) or on heat air comes out under the dash. But nothing out of the vents in front on the dash. Checked all hoses under the hood, nothing loose, cracked, or not connected. However, there is a noise like something is leaking/blowing air maybe behind the dash. Sounds like it is right behind the controls for the vent/heater/ac. Noise is still there when I turn the air control completely off. And it seems to almost go away as I accelerate. Does that make any sense? WTF?

So just cause I was curious I tore apart the dash last night, but I really don't know what I should be looking for.

Anyone have any ideas? Any help would be appreciated! :)

By the way... I have been driving it for two weeks after replacing the lifters, and everything was working fine...and then just a day ago this.

The vacuum line probably has come off the back of your heater control or it has a hole in it. The noise you hear is the air sucking. You was on the right track just find the hose and if it is not unplugged check for holes and if you don't find any holes check around the control itself to see if it is leaking.

Thanks for the reply alblogg!

This may be a stupid question, but I am not entirely sure I am looking in the right spot. Am I understanding this correctly, that a vacuum hose comes directly through the firewall to the control on the dash for the ac/heat/vent?

I tore this apart last night again and I did not find any hose connecting to this. I am just wondering if I misunderstood. Is there more than one vacuum hose in the dash?

There is a vacum line that goes to the back of the control. The blend control is vacum operated.

Yes and if you are hearing it inside it must be it crank it up and see if you can find the sucking sound. If you did not find one on the back then it probably has slipped off. You might have to feel around until you find the hose sucking. Remember GM does not leave much slack on anything.