So now that my brat is becoming more and more done, I'm getting ready to tackle the heat. Well, lack of it. When I turn the dial absolutely nothing happens. I deleted the a/c, but it wasn't working before that anyway. Where should I start my chase for the fix of the problem?

 

Down the rabbit hole I go.....

go to the other end of the cable at the heater tap under the bonnet and watch as someone else operate the inside dial. Mine was slipping. Secured with a zip tie after cleaning tap unnecessarly nice heater shut of in summer finally, and now autumn is here ...toasty when required.

It's the dial that isn't functional though, which I don't think moves anything under the hood

Its under the dash, on the left side of the center console. Turn your knob and look for movement. Once you see it you will understand.