2002 trailblazer ls- turn on ac or heat and nothing blows out, all fuses are good. Anyone have a suggestion? Thanks.

 

I would suggest checking the blower motor resistor. Its right under the glove box. Takes about 30 min to replace and fairly inexpensive.

 

will do - what does it look like and how would i know it is bad? thanks

 

Gm wants $45 after market $23 . Remove the plastic panel under the glove box it is attached to the blower motor . Follow the purple wire. 2 screws hold the resistor. Coulsd also drop down the glove box to reach the connection to the blower motor easier