A vehicle air conditioner comprising: an air conditioner main body section including a housing that has an air flow passage provided inside; a first fan that feeds air guided from inside of a cabin and/or outside of the cabin to the air flow passage; an evaporator that is provided in the air flow passage; a heater core that is provided downstream of the evaporator; and a temperature regulation door that is provided between the evaporator and the heater core and that regulates a ratio of air heading for the heater core to air bypassing the heater core; and a duct unit for rear seats that is connected to a downstream side of the heater core in the housing and that guides conditioned air temperature-regulated by the air conditioner main body section to rear seats of the cabin, the duct unit for rear seats including a second fan that suctions and delivers the conditioned air and a duct for rear seats, the duct unit for rear seats having a second fan driving motor that directly drives a centrifugal fan accommodated in a fan case of the second fan by a rotary shaft, wherein the vehicle air conditioner comprises: an air guide port that opens to the housing to guide air for cooling a motor from downstream of the first fan and upstream of the temperature regulation door in the air flow passage; a guide passage that guides the air for cooling the motor guided from the air guide port to the second fan driving motor; and characterised by, a discharge passage that discharges the air for cooling the motor after passing through the second fan driving motor to the cabin. an air conditioner main body section including a housing that has an air flow passage provided inside; a first fan that feeds air guided from inside of a cabin and/or outside of the cabin to the air flow passage; an evaporator that is provided in the air flow passage; a heater core that is provided downstream of the evaporator; and a temperature regulation door that is provided between the evaporator and the heater core and that regulates a ratio of air heading for the heater core to air bypassing the heater core; and a duct unit for rear seats that is connected to a downstream side of the heater core in the housing and that guides conditioned air temperature-regulated by the air conditioner main body section to rear seats of the cabin, the duct unit for rear seats including a second fan that suctions and delivers the conditioned air and a duct for rear seats, the duct unit for rear seats having a second fan driving motor that directly drives a centrifugal fan accommodated in a fan case of the second fan by a rotary shaft, wherein the vehicle air conditioner comprises: an air guide port that opens to the housing to guide air for cooling a motor from downstream of the first fan and upstream of the temperature regulation door in the air flow passage; a guide passage that guides the air for cooling the motor guided from the air guide port to the second fan driving motor; and characterised by, a discharge passage that discharges the air for cooling the motor after passing through the second fan driving motor to the cabin. an air guide port that opens to the housing to guide air for cooling a motor from downstream of the first fan and upstream of the temperature regulation door in the air flow passage; a guide passage that guides the air for cooling the motor guided from the air guide port to the second fan driving motor; and characterised by, a discharge passage that discharges the air for cooling the motor after passing through the second fan driving motor to the cabin.