I can't find anything in the manual about shutting the AC off when you turn off the engine. My truck AC has the auto feature where it controls everything, you just set the temp. So i would like to know if i should leave the AC on when shutting off the engine or turn it off ?

I leave mine on, its nice and cool with the remote start.

Leave it on. I doubt very many shut it off before shutdown. The cool think about the auto climate control is that if it is not needed next time at startup, the ac will not come on.

I don't have the automatic A/C in my truck but I am from the old school and always turn mine off about a block from home. It may be stupid but my dad always did this when I was a kid, he said it let the pressure bled down, or something like that. Anyway I think that the the AC is turned off then the key is turned off , so the starter isn't trying to turn the compressor when you try to start it.

the only time i touch the dials on my ac is when my wife goes messin with it.... all the worries about the ac are handled by the trucks onboard computer.

If you want to say something, shut A/C down about 30 sec to 1 minute before you shut car of to lose some extra under hood heat for it before it sits, otherwise turning it off right at shutdown saves nothing.

I shut it down a block away from the garage just to let the ice and water drain off of the evaporator just to keep mold from growing. I dont know if it helps or not but it seems logical.

Water will drain off a lot longer than you think. More than just that block away drive from your garage.

I've always heard you should turn off the recirc a few minutes before shut down to reduce humidity/condensation in the ducts. That is supposed to reduce the moldy smell some AC units get. Edited by: BadDog

Trust me, a "car" gets hot enough setting to cook any moisture and mold out of ducts most of the time.