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).

Any suggestions/ideas are most welcome.