HVAC - Flap in the Breeze

:goof:
Thinking it was something we did while installing the wiring for Tone's popper-kit, I've pored over this problem and still can find no cause/solution.

Whether in "automatic " or when manually switching the HVAC to the left-most setting that directs all air-flow through the front vents on the dash-board, I can hear the sound of a flap closing and air-rusing from the blower behind the glove-box, but no air will flow through the dash-board vents. Nor does air come from them when selecting "dash/floor" circulation. However, air continues to flow from the floor vents and from the windshield/defogger vents, normally.

When selecting dash-circulation, it sounds as thouh something is closing, then blocking airflow and diverting it behind the glove box. I've dropped the glove box and can't seem to determine how air makes it from the blower to the dash vents. I'm about to climb in there, again, with some mirrors to see if there is something I'm missing that's hidden from view.

Are the VehiCross a/c system controls electronic or are they operating on compressed-air? Just wondering if there might be a hose loose in the latter-case.

The A/C airflow diverters are operated by levers and doors, actuated by vacuum dashpots. The "Default" resting place I believe is the heat setting (Floor & Defrost). Sounds like a rod may have slipped off or you have a vacuum leak in one of the dashpots..

OK, now it gets really weird. I thought I had nthe problem solved when I rerouted the under-dash hot-wire for Tone's popper switch (which I placed on the left side of the glove box frame).

Air seemed to be flowing freely from the dash-front vents.

Later, I turned on the system while driving. I usually set it on "AUTO" and let the thermostats figure out where the air is needed. However, as soon as it got revved-up, something shut the air-flow to the dash and rushing air is, once again, blowing from behind the glove box.

I've tried this several times. Each time, I have to turn off the system, then restart with the blower fan running at a low to moderate speed. Basically, high-fan settings seem to have a relationship to the dash vent gate being closed.

I'm unfamiliar with the vacuum dashpot operation of the HVAC system in my VX and there appear to be no obstructed rods or other moving parts (that I can tell). :confused:

Any suggestions/ideas are most welcome.