I have a 2003 trailblazer lt 4.2. the AC resistor went out so when I turn the tb off the blower stays on. I have tried to look into how to install a toggle switch for on and off but I don't get the results I'm looking for so maybe someone here would know how to wife a 3 prong toggle switch up to turn on and off my blower without taking in and out the blower fuse I really appreciate any help thanks

 

Scratching my head, does the blower just stay on with key on, and same speed? If it stays on the same speed, what speed is it?

 

It stays on when the truck is off obviously stays on well on only way to keep it off so it don't drain my battery is to take the fuse out. It stays like 2 notches for Max I have the manual temp I pick the exact temp I want

 

Well, I'd say the switch is bad. You can do as you said add a toggle switch, but I'd replace the existing one.