To provide a control device for a vehicle capable of meeting the required air volume to a capacitor even if its switching module is of low cost type driving a motor for a cooling fan of an air-conditioner for the vehicle.

The control device of the vehicle having the switching module to supply the effective voltage determined by the duty ratio command value and the supply voltage to the motor for the cooling fan, is equipped with means 21 and 26 capable of controlling variably the power generation voltage of a generator 2 in conformity to the voltage command value, a means 21 to calculate the target duty ratio in compliance at least with the outer air temperature, and a first setting means 21 to set the target duty ratio as it is as the duty ratio command value when the target duty ratio lies below the upper limit value. The arrangement further includes a second setting means 21 to fix the duty ratio command value to 100 % when the target duty ratio exceeds the upper limit value and set the voltage command value so that the effective voltage equivalent to the target duty ratio exceeding the upper limit value is supplied to the motor 12.