The blower motor wiring was reversed. It hit me in the middle of the night that the blower might be running backwards. So I pulled it out and checked whether it was turning the right way to get air through the vents. It wasn't.
It came that way from Auto Zone. This was the less expensive model, "Continental part number PM3923",
with the connector on a pigtail. It was easy to reverse the pins on this connector.
I was able to pull the oval shaped red rubber holder out of the connector shell from the pin side, then used the small screwdriver on my leatherman to release the retaining finger (towards the middle) on each pin. I then had to re-bend the retaining fingers since they were now flat, and put them back into the shell in the opposite order. Inserted pins until I heard the click of the retaining finger and verified they couldn't back out. Then I just pushed the rubber holder back in, connected it up, mounted it, and *presto*, I had air flow.
The way it was originally wired, I had a blower to exhaust heat (or cooling) from the vehicle!!
That's why the airflow felt weak; it was drawing air into the vents rather than pushing it out!