My Carrier 58MVP120F15120 HVAC mulfuntioned. Blower would not start. I found responsible for failure component as thermistor or varistor (not sure) TR01 on the PCB board inside control unit of the blower motor.Unit is mounted in the round steel case on the face of the motor. Part number of this element is SG348 and looks like disc, size of a dime with 2 legs. One of them disconnected. Part number of complete control unit is DG02 0200GX made by GE for 3/4 HP motor. 1. Does anyone know specs for SG348? 2. Any sugestions for replacement. 3. Availability of spare part or control unit.