Wild cabin heat temperature variation

hillcountryredneck · January 20, 2014

First post so take it easy.

During long extended trips in cold weather, we turn the heat to around 70-72.

Cabin temperature soars and need to turn it down to low 60's or on LO.

Generally takes awhile for temperature to respond back to a cool temperature and then we are back to turning back up...

Something has to be up with sensor, location...

Ideas???

Silverado Steve · January 20, 2014

Any chance you're running the front defrost?

Jeff48 · January 20, 2014

Mine is really touchy too. At 72 it seems hot, then 71 blows cold. I started using auto and it is perfect to me now.

Dozzer LTZ · January 20, 2014

Does this happen when its on the auto setting or manual?

dagwood2001 · January 20, 2014

Any chance you're running the front defrost?

yea i've had similar problems and the front defrost seems to be a culprit. Also, as Jeff above states, 1-2 degrees seems to make a huge difference on whether you get hot air or cooler air. Once things get settled in, I'm good, but getting there can be a bit of a pain.

Interesting to note I have had zero problems with the AC-I bought the truck in August when it was still hot and the AC was awesome. It's only the heat that's hinky......

diannabill · January 21, 2014

First post so take it easy.

During long extended trips in cold weather, we turn the heat to around 70-72.

Cabin temperature soars and need to turn it down to low 60's or on LO.

Generally takes awhile for temperature to respond back to a cool temperature and then we are back to turning back up...

Something has to be up with sensor, location...

Ideas???

Your username suggests to me Texas Hill Country? Lots of sun coming in through glass directly on your skin? Maybe it's not so much the cabin temperature as the sun reflecting through the glass onto you. Just a suggestion.

dmd277 · January 21, 2014

I have observed the same thing on heat, I have a hard time getting it to blow a comfortable temperature. I have been leaving it in manual.

mdes0 · January 21, 2014

My climate control sucked too. When the tuck went in for a leaking roof the dealer did teh fire update and found a climate control software update. Seems to work much better. Still not as good as most systems though.

hillcountryredneck · January 21, 2014

Still get cool temps in these parts of the Texas Hill Country. Noted conditions during extended traveling to far cooler climates to the west.

Controls set on feet/dash, not defrost, not defrost/dash, not synced, not on auto...

AW22 · January 21, 2014

Ditto on my Sierra. The difference between 70 (warm) and 68 (cold) while using heater either on either auto or manual is way too extreme..ie when turning down from 70 to 68 the air temp blowing out of vents is much more than a 2 degree drop. With or without AC running for the auto mode. It was between 30-40 over the past weekend here in CT. Weird, but obviously not alone. Wonder if there is broader service bulletin for this.

blckthree · January 22, 2014

I leave mine in Auto all the time, never seem to notice any big temperture differences. When you first start it and it is warming up or cooling off in the summer, there will be a bit of time before it regulates itself, but after that, it works pretty flawless.

Mike

2fst4u · January 22, 2014

Mine works awsome no complaints! Auto here as well. Defrost works well when windows are frosty other than that auto works great. Even when wifey likes warmer on her side things work great!!!

crushNchowda · January 22, 2014

I too notice it varies greatly, but I think it has something to do w/ the auto climate control/hvac out-thinking itself. I think it senses the outside temp say, at 12 degrees, and I ask it to do defrost plus lower fan on auto at 72 degrees. There are tiny vents for the front door windows and the defroster for the windshield blowing super hot to remove fog and combat the extreme cold while the rest of the vents are fighting against this action blowing cooler air to combat it and come down to the desired 72 degrees I entered.

I also think its because I can feel the hot defrost air from the small side vents on me directly.

I believe if left on auto at a reasonable temp it may work better too rather than raising and lowering drastically manually to get it where you think you want it.

I also agree no troubles in the heat only the cold weather, I've been having better function leaving it be in auto as I said

AW22 · January 22, 2014

Related question. When in auto mode regardless of the outside temp my AC is on. On an older vehicle I recall AC would not switch on under a certain outside temperature. Is the AC actually running when in auto mode if it's 10 degrees outside? Would seem unnecessary and not exactly max fuel efficient I would think especially when AFM has engine running 4 cyclinders.

2016 Sierra Owner · January 22, 2014

Just because the light is on does not mean the compressor is running. It's usually on in the cold weather to remove moisture so your windows don't fog up. As for running in V4 it no different than when it's warm out it will still run the A/C for you. The truck does not ideal in V4.