A method of operating a vehicle climate system when an ambient temperature is below a threshold temperature is provided. In response to an ambient temperature being less than a threshold temperature, a controller is adapted to operate a blower motor at a voltage that depends on whether the vehicle is in charge sustain mode or charge deplete mode. In response to an ambient temperature being greater than a threshold temperature, the controller is adapted to operate the blower motor at a voltage that does not depend on whether in the charge sustain or charge deplete modes.