The rear defroster will shut off sooner. The hotter the rear grid gets the resistance changes and solid state logic in the hvac unit shuts it off.
I don't see how they could have grabbed power at the hvac Controller to power the alarm and since I've never done it on any 04+ gp I'm sure they didn't either, Maybe hooked it up for a trigger to turn on the defroster but that's it. The BCM has several 12v orange power wires that's suitable for powering an alarm.
Don't use velcro it reduces vibrations. Zip tie it to the steering column for best results.
Sent from my Galaxy SIII on Tapatalk 2
