Ive always noticed that if Im running the AC, and turn the car off, then move the AC knob to the off position, I hear the internal doors move and the system sortve depressurize and let out a pshhhhh sound. It does it on my 03 f150 and it did it on my 98 mustang. Call it OCD, but out of habit I always make sure its turned off before I leave the car for the evening or where-ever. As if to make sure the system isnt holding some kind of pressure. Im guessing it doesnt make a difference what you do, or does it? One of those funny habits.
When the AC compressor shuts off, the refrigerant pressure in the system will equalize no matter what else you do.
I agree. My AC switch stays in the same position basically all summer long.
Yeah, just a weird habit I guess.