My 2006 gmc sierra defrost blower doesn't work I checked the fuses any ideas

Make sure you check fuses with a test light or ohmmeter, because just looking at them is not good enough sometimes.
Have you tried high speed, because the lower speeds use resistor packs that can burn out. They are between the switch and motor, usually in the air box. While there, you will be able to see if the switch is bad, if a test light shows anything. If there is power right at the fan motor, and ground, and it still does not work, it has to be the motor itself. But hope not, because hard to get to.