Blower motor of speed control method for battery voltage of full automatic temperature control

A method for controlling speed of a blower motor for battery voltage of an automatic temperature controller for a vehicle is provided to offer regular airflow regardless of voltage changes by classifying input battery voltage and varying PWM of a switching element. A method for controlling speed of a blower motor for battery voltage of an automatic temperature controller for a vehicle comprises the steps: detecting battery voltage inputted to the vehicle(S11); classifying detected battery voltage for each level(S12); varying width of switching element PWM(Pulse Width Modulation) of the blower motor according to the classified battery voltage(S13); and driving the blower motor considering varied PWM width(S14).