The blower motor is a squirrel-cage fan with a motor attached that pulls air through the evaporator coils and blows it through the vents in the dash. As a general rule, if the blower isn't running (with the climate control on) look under the hood and see if the compressor is running. If the compressor is on (is turning with the pulley), then your blower motor is probably bad. A simple check for the blower is to use a voltmeter and see if the blower is receiving current.. If the blower is receiving the proper current and isn't working, the blower is the problem. If current is not reaching the blower, then the problem is further upstream in the climate control system, such as the pushbuttons, etc..