Inducer fan will not shut off when tstat calls for heat in occupied mode, but then setback temp/time for tstat says stop call for heat. So just as tstat says stop the call for heat, and it yet has fired up, the inducer motor will just keep running. What controls this functioin.

Not very savy with Armstrong,but most I`ve ever worked on the inducer ,like most every other part of furnace is controlled by the circuit/control board
,can you trace the wires hooked to inducer and find where they are tied to?

That will be my next step, appears to come from control board. When inducer fan stays on, I actually have to remove black power wire that feeds this fan from a relay. So could it be this small relay? Control board feeeds 24 volts to this relay.

Yep, probably the relay,, in most cases you can`t replace just the relay, its made in and part of the control board (means replacing the board