I have a 2002 Trailblazer. When you put it on the 5 setting on AC it sometimes blows but then will quit or it won't come on but then after a while it will come on but then go off. It has now started on the # 3 setting. Any ideas and how easy is it to fix and is it costly?
Thanks To All Who Respond

blower motor resistor. under glove box

blower motor resistor is under glove box