How did i end up with a dodge answer when i have a trailblazer? Whatever the fix is same.
Rule #1) never have the blower motor on high & Never for extended periods of time. The parts, no matter where you buy them, are all made from the Peoples Blower Motor & Wewista Factory, located in China. Chevy has discontinued that brand for obvious reasons. Chevy has also redesigned wiring for the resistor in which a diagram is provided in a kit with a new cable assembly which you have to re-assemble yourself. Problem is the new wires are all colored the old wires are all purple. The diagram doesn't point out which colored wire will go to which purple wire you removed from the PCB (printed circuit board) YES a soldering iron, flux, ability to solder without Burning the $@$* out of the PCB components is required. Luckily there is a 800 number I believe to call for technical support. I never used it. The good news is you probably dont have to replace your resistor. Its the blower motor. They are cheap made in China & blow up every year because “where ya gonna go? What ya gonna do?” China makes the only replacement parts at the Peoples Blower Factory. American companies buy the same part and slap an American brand name on it. The dealer recommends you buy a used part off eBay, they will have a photo & just make sure the part u buy isnt from China or “PRC” -which theu are using now to make you think its not made in China prc=”peoples republic of China” . Time to replace is 15 minutes dont be shocked if job of replacing the resistor board takes you a day and a half. My advice replace the motor. The resistor i bet is fine. The motor replaces very easily. However considering this is my second time replacing it in one year, and God knows how many times it has been replaced in the last 15 years, the screw threads to hold it are damaged. Prepare for that possibility because it must be bolted if it isn't bolted with the three screws it will wobble and that will break it even faster not to mention a bad noise. Enjoy