HVAC Controls - How to really turn off A/C?

mc2032 · April 22, 2014

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oldscsc · April 22, 2014

Not sure on the 2014 models, but all the way back to at least 1999, the recirculation button engages the compressor regardless of blend door position. Having any air going to defrost the windshield does the same thing.

The purpose of this strategy, both with recirc and defrost, is to reduce humidity.

surebuttercringe · April 22, 2014

I don't know if this is a GM thing, but my 2004 GMC Sierra did the same thing. My wife was always complaining about her feet being cold because there was cold air blowing on her in the passenger seat. In my F-150, off mean off and there wasn't any air coming out of any vent.

gSwift · April 22, 2014

On my 2014 I hit the off button and then hit the recirc button. I think even if its on recirc while its on and then you turn it off, it defaults to the fresh air setting.

8.1HD/ALLISON · April 22, 2014

Recirculate is A/C. Any vehicle I have ever seen, gm or not.

Sent from my LGL86C using Tapatalk

mc2032 · April 22, 2014

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Crf450r420 · April 22, 2014

You might be able to pull the fuse, but it might also take out the fan. Modern systems will not likely get you another .5 mpg, but pull the fuse and test it out to be sure. The systems automatically control the A/C since most people didn't know the air always runs through the evaporator and it can also be used to remove water from the air even with the heat on.

oldscsc · April 22, 2014

Driving across Kansas and Nebraska you get to experience many "strong" odors plus dust and chaff, etc, so recirc comes in pretty handy. Too bad you have to have the A/C running on a cool day to get the benefit of a cabin air filter and/or no dust/smells. There are two seperate buttons, A/C and recirc, I would like to be able to pick and choose. But it looks like that is not going to be an option.

Off topic, i hate the engine braking feel of the transmission during decel/coasting. and if you kick the transmission into neutral during decel/coasting the engine does not idle down but holds RPMs same as road speed. so, no go on being able to "roll" up to the stop sign, looks like i will have to keep my foot in it and drive up to the stop sign then brake. i ilke this truck but kinda feel the engineers over thought a few things (i'd say failed but that might be too harsh).

A) Any air flowing through the system, whether heat or AC, fresh air or recirc, will be run through the cabin filter.

B) The decel feature is annoying for those used to coasting to a stop sign; however, while engine braking, the ECM will not command the injectors on or will utilize them very minimally = increased fuel economy. Idling the engine is inefficient and anytime you brake, energy spent in the form of burned gasoline is wasted and converted to heat when you apply the brakes. That energy can be used to power the engine upon deceleration.

PickUPS · April 22, 2014

Off topic, i hate the engine braking feel of the transmission during decel/coasting. and if you kick the transmission into neutral during decel/coasting the engine does not idle down but holds RPMs same as road speed. so, no go on being able to "roll" up to the stop sign, looks like i will have to keep my foot in it and drive up to the stop sign then brake. i ilke this truck but kinda feel the engineers over thought a few things (i'd say failed but that might be too harsh).

Coasting in Neutral works great in my 2014 Sierra V6. The engine idles-down and the truck will coast further than any vehicle Ive ever driven, thanks to the new drag-free brake calipers.

Ive had the truck for less than a month. At first I didnt like the way the trans backdrives the engine while coasting, in order to turn off the fuel injectors. Now I actually prefer it in some situations. In city traffic or any time I have to slow down without much advance warning it is very effective to leave it in Drive. The truck slows itself using some of the momentum energy that would have been turned into brake-heat. Leaving it in Drive can save fuel, save brake wear and make the truck just a little safer.

Other times, when I am on a down-hill and trying to maintain or increase my speed in the most efficient manor, Neutral costing is very effective. The truck actually increases its speed on the way down a hill and coasts part way up the next hill. I put it back in Drive before it slows back down too much and motor on.

For me, having the choice of two ways to coast is really better.

The OP's engine should return to idle-speed when in Neutral. The only time Ive heard of an engine remaining revved while in neutral is in the case of some Toyota manual shift trans that keep the revs up to smooth manual gear changes.

kstruckcountry · April 23, 2014

Don't kick the tranny into neutral while you're driving, that's completely unnecessary and like others will tell you actually less efficient.

The AC knows what it's doing, it's controlling the humidity. I wasn't aware they had a cab filter again.

mc2032 · April 24, 2014

Figured out that the A/C is always on with recirc. Okay, I am good with that, will just have to get used to outside air or turning the tmp know up a click. Can't change how GM set it up, so adapt and go on. Did pop the lower glove box door/cover off and pulled the cabin air filter. Was impressed with how much dust the filter has trapped in 4300 miles of hiway driving. Good on you GM for reintroducing the cabin air filter. Looks like all cabin air gets pulled thru the filter regardless of outside air or recirc. Wish GM would have put that in the manual, and maybe it is, I just have not found it.

Am learning to drive down the coast/roll up to a stop. drive by wire, feather the throttle and it is just about the same as having the transmission kick out. must be a function of the electric controls of the transmission that doesn't let it free wheel as much as I think it should. and, an honest 23 mpg in city is okay with me. I don't hot rod on road as much as I used to so the mileage doesn't suffer like it use to when I had a lead foot.

thanks for all of the replies.

TX14Z71 · April 24, 2014

How do you access/change the cabin air filter?

mc2032 · April 24, 2014

four torx head screws common to the glove box surround. two top, two bottom. remove them and pop the surround off/out. directly behind the glove box is a 8 inch wide by two in tall cover w/ two snap clips. pop the cover off and there is the filter. the top two are easy to get to/see. the bottom two you have to almost stand on your head to see them.

SnakeEyeSS · April 24, 2014

four torx head screws common to the glove box surround. two top, two bottom. remove them and pop the surround off/out. directly behind the glove box is a 8 inch wide by two in tall cover w/ two snap clips. pop the cover off and there is the filter. the top two are easy to get to/see. the bottom two you have to almost stand on your head to see them.

If you really have to remove 4 screws for a cabin filter, that's some seriously crappy enginering. They have obviously never compared their product to a competitor. Makes you wonder.

mc2032 · April 24, 2014

well, the filter is supposed to be good for 25,000 miles so accessing it isn't something you should have to do very often. and compared to the cupholders, the cabin air filter design is perfect.