I seem to recall that there is an engine coolant temperature sensor attached to one of the heater matrix pipes that would prevent the blower motors from ramping up to speed until the engine temperature was at least luke warm.
Mine is blowing at or near high speed out of the heater ducts at 10 °C or a little less maybe.
Am I being forgetful again, or just crazy? The schematics in RAVE clearly point out the connector and pin for the sensor.
And why do instrument lamps seem to go out when it's too cold to hold a screwdriver and the plastic is brittle? (that's a rhetorical question. I know the answer).