How to replace a Blower Motor, The Blower motor is the fan that pushes the air out of your vents, many times if you don't have air coming from the vents it will be the blower motor that fails, however there can be other things besides the blower motor that can cause the same issue, such as a Control Unit, Resistor, Wiring, Connectors, A way to check if it is the blower motor is to strike the Blower Motor with a blunt object while the a/c is on high speed and see if the air comes on while you are hitting the bottom of the motor. If it comes on you know the Blower motor is bad, if it does not consider other options. If it is a dodge ram it is common to be the ignition switch, which gives power to the control unit for instance.