Thanks to ZTom for peaking my curiosity concerning the blower resistor.
The fan speeds worked as they should as long as the resistor was out of the evaporator box. I started pushing the resistor into the box with the fan speed on low and as it bottomed out, the speed switched to high. Evidently over the span of a week, the expansion valve copper coil sprung back and made contact with the resistor. I think this is the first ever "free" fix for me.
