variable speed blower motors are ECM motors, identified by the large control module on the back end and 2 wiring harnesses - one for power, the other for control signals. these require a true RMS clamp meter to read amps. the common averaging meter will read high, i think. plugged filters and coils, blocked/small returns will cause an ecm to draw more power as it tries to make programmed rpm against the restriction... support your local tradesman, get a full pm/cleaning! also depends on how the unit was set up - usually some way to select blower speeds for heat and cool with constant fan defaulting to a small percentage of either heat or cool speed.