blower motor stopped working on 2003 GMC Yukon

blower motor stopped working. and worked the next day, but now has been a week and it's not working. I took out blower motor and bought a whole new one and it didn't work, so I bought the resistor moduele, still doesn't work, I checked all fuses and they are good....could it be the relay switch? where are those located?

Asked by for the 2003 GMC Yukon