2003 rear blower not working

I have a 2003 Chevrolet tahoe that the rear blower has quit working on. I have replaced the resistor and it does not work. You can hear the clicking coming from the resistor when it is repositioned in the 3 position. It is manual control and there is no sunroof as it is a Police package. Please help it is blistering hot and no rear a/c is a problem in Texas!!!!!!!!!!!