So, in speaking with somebody "in the know"...
The radiator fans will run until the thermostat tells them not to.
and
If the interior fan doesn't want to turn off, splice in a resister to the wire supplying the low speed setting. Radio shack part number 2761141, I think he said it was a "3 amp 50 PRV" resister (whatever that means).
There it is, my small contribution to the forum...repeating information told to me by someone who knows what they are doing. (btw, I would like to give credit where credit is due, the Olthoff shop is the "go-to" shop for all things SPF. I'm sure that there are others, but they've always been very helpful).