Can't select vent, defrost, etc...help

[MalingatorGTS]

Well my fan is working and I can hear the air speed change when I use this control knob. However, when I try the selector knob, vent, defrost, etc nothing happens. It does come on when you switch it on to start air moving but it's not coming out anywhere. It sounds like the air is
trapped behind the dash.

Can someone point me in a direction please. The car is down for the rest of the week waiting on a part so it's a good time to figure this out.

I'm guessing it may be the re-circ door/flap is broken or stuck but I don't know where to find it on this car.
Thanks in advance!!

[AZTVR]

Well my fan is working and I can hear the air speed change when I use this control knob. However, whetn I try the selector knob, vent, defrost, etc nothing happens. It does come on when you switch it on to start air moving but it's not coming out anywhere.

Does the knob action feel right? I know that the Jeep climate control knobs (similar looking setup by Chrysler) have a propensity for breaking (2 out of 3 broken on my 2002 Wrangler) and they just turn; but, don't move the shaft. That would be my first look. However, I have not read of this as a common failure mode on Vipers.

[Tom Sessions]

Check and see if the air is coming from the defroster. When the system is in the relaxed position(no vacuum) all vents switch to defrost. It may be as simple as a vacuum hose off at the intake or on the rear of the control panel

[MalingatorGTS]

Thanks for the quick reply. It feels like it's falling into position correctly, ie not just freely rotating and stops on each setting. I think the knob is working properly as it turns the air on/off. My guess is if it was spinning and not changing as it did it wouldn't turn on.

[MalingatorGTS]

Check and see if the air is coming from the defroster. When the system is in the relaxed position(no vacuum) all vents switch to defrost. It may be as simple as a vacuum hose off at the intake or on the rear of the control panel

Thanks. My first attempt was switching it to defrost. Nadda. So if it is a vacuum line where should I start to look? As stated behind the bezel itself or elsewhere?

[Fatboy 18]

If you lift the Hood, just in front of the passenger window are the flap controls, check to see if the end of the cable has become detached from the controls. Also on the side of the air box there is a small round black vacuum canister with an arm on the top of it, Check to see if the arm is attached? There should be a C clip holding it in position.

Both of the above have become detached in my 7yrs of ownership

[MalingatorGTS]

If you lift the Hood, just in front of the passenger window are the flap controls, check to see if the end of the cable has become detached from the controls. Also on the side of the air box there is a small round black vacuum canister with an arm on the top of it, Check to see if the arm is attached? There should be a C clip holding it in position.

Both of the above have become detached in my 7yrs of ownership

Thanks! The car is up in the air on stands right now over a busted half shaft. I hope to get a new one in Saturday morning and then get under the hood and check out your suggestions.