I've always wondered why vehicle manufactures have used shaded pole motors and resistor blocks for their cabin air. Why not a psc motor and forget the resistor block? I do believe they use them now, or at least an ecm motor. But why now? Psc motors have been around for a long time. I have a ford escape I'm going to put a psc motor in and block off the hold for the resistor block. I forgot to unplug it when replacing the heater core. Rather than breaking off at the connector it tore a hole in the heater box. Hence the reason I had the idea of a psc motor. I plan on doing the same to my ranger if the resistor block goes out, and it works out on the escape.