Just because the A/C light isn't on, doesn't mean the A/C isn't running, it operates on Auto, and in Defrost mode as well. If you have the truck set to a temp and on auto and remote start the truck, it will use the A/C to cool the truck. I have a Laramie as well, this is how mine works.I think the Air Conditioning only comes on if you left the A/C on; that is the only way mine comes on with the remote start. My cooled seats come on with remote start without having to "preset" them; but my A/C does not. I have a Laramie with Automatic Climate Control.