Goodman, Model AW3682-08C (I think... it's hard to read... original install 10 yrs). New coil, new thermostat. Everything just fine until recently, the inside blower intermittently fails to turn on when set to Auto, then coil ices. If I run the unit with fan in "ON" position, cooling seems to operate correctly above and below the ambient temperature.

Thanks for your help! :)

Odds are you have a control board acting up.

Yep the fan relay which is usually located on the control board is intermittent or the wilring has a loose connection.