Answer by  
                                                                                          TheRealPlumber (249)
                                                            
                          
                          
                                                          This a simple question, the fan motor or speed controller could be burned out. If there is power to the A/C unit then this would be the only answer. You will need to verify power to the A/C unit, if power is available at the unit then you will need to replace the fan or controller. Consult a Pro.