I having an issue with my 03 ss a few days ago my heat was working until I stopped at the store then nothing. For about a week prior to this occasionally I would hear a small squeaking noise for a brief second then it would stop. Now I have no air blowing out of any speed and my defroster isn't working either. I could really use some help it is getting to cold for no heat. Any helpful ideas would be greatly appreciated. Thanks

 

The blower motor could be bad

 

I agree with `John above.
When you're driving is there heat flow from the vents ?
How old is your thermostat ? Sometimes they stick (?)

Does air blow when you turn on your heater/air switch ?

I suggest dressing warm until you find & fix the problem.
Good Luck

 

Do the fans come on when set to hot or cold? Or is there just Jo heat. If no fans the first thing I would check is all fuses especially for the defroster. Is the rear defroster acting up as well? Deff check the fuses is they ok then next would be the blower motor