Fan was bad. $40 from NAPA. Fixed.
All much easier to diagnose and replace after a Forum member told me the radiator shroud (to which the motor mounts) is only held in place by the two, easy to get to, hex head screws at the top. Removed screws, pulled up shroud, could easily access two conductor connector. Fan was "open" (infinite resistance on ohm meter). 12 volts available across input connector when A/C selected. NAPA replacement was exact and easy after I remembered the center hex head nut for the fan is counter-threaded = clockwise to remove. Installed new, replaced shroud. Did have to go under and guide the bottom edge of shroud into two steel spring clips. Again, easy.
[This message has been edited by John W. Tilford (edited 07-05-2020).]