Auto Heat/Cool Inop (mostly)

[kwiebe]

300C with dual zone auto heater/AC control. To get heat to come on, have to crank dials up to last couple of notches.

Is this common, certain component to blame, like a sensor?

[Mr. iNCREDIBLE]

the system works kinda funky IMO..

this is what I have noticed..

the system uses the outside temp sensor, as well as the inside temp sensor (the little "eye" on the HVAC controls at the top) and the sun sensor on the top of the dash.

it attempts (rather poorly) to determine the temp and balance it.

if the outside temp is reading 75 degrees, and you have the HVAC temp set at 75 degrees, and the inside temp is a bit warmer from the car sitting all day, then the computer thinks the car is at the correct programmed temp and won't turn on the A/C or heat.

I've discovered thru trial and error that you have to set the temp 5 - 10 degrees above or below whatever your outside temp reading on the EVIC is displaying, otherwise the system won't kick on.

in comparison to my GF's Camry Hybrid with dual zone, our system sucks. The Camry system only cares about the internal car temp, and using a old fashion thermometer, I can verify the Camry is cooling or heating the car to the set temp on the digital display at it will turn on and shut off within 2 degrees of the setting, our cars don't, it is always 5 - 10 degrees off, but such is the problem with old style analog dials.

[kwiebe]

Thanks. What really got me wondering tho, is the fact that my 06 Magnum seems to work much better than the 300 (still not perfect).

[kampsvilleboy]

I had an '05 300C with the auto climate system that worked perfectly. I never touched the temp control. It cooled when it should and heated when it should. My '09 300C seems to not work too well though. A couple of times I've gotten into the car and waited and waited for the air to kick on as the interior seemed to get warmer and warmer. Finally I had to crank the temp knob all the way to the coldest setting to get some A/C to start coming out of the vents. I once tried shutting the car off and restarting and that seemed to kick the A/C on.
If I had never known anything different I might say this is a Chrysler quirk. But my '05 worked as it should so I know Chrysler can make a climate control that functions properly.

I haven't had the time to have the dealer look at it yet, but I intend too.

[ReppinTheSouth]

I have the same problem. I actually was looking for a post about this. I don't leave it on auto setting which might be problem but what I experience is for me to get heat, the knob needs to be on the last knotch. When I even turn it back one knotch, it gets icey cold. That doesn't seem to be right to me.

[MIDNIGHT451]

Same here, it was great at first and it seems over time it's just acting screwy

[S4-2-300C]

Mine blows too. It never seems to know what I want. In my S4, I set it to a temperature and that was it. 12 hours later the car would have never changed temps, even if it went from 100 degrees and sunny outside to 10 degrees and a midnight blizzard. This thing usually seems more confused than my roommate in college. I imagine it really sucks for people with small children. How the hell can you leave them little bastards in the car at a comfortable temperature while you shop around in walmart???

[ray_m]

My old 1985 Mercedes has a relatively simple system that uses an air sampler and a small fan that draws cabin air over it. In the winter it waits until there's hot water, then does full blast heat, and then tapers off as the set temp is reached. Similar in the summer with A/C. I wish the 300 worked the same way.

[MIDNIGHT451]

This is great, my auto hi and low back light is starting to go after posting. I have to tap it to go on.

[ReppinTheSouth]

Well, I think I made some headway on mine. Up until I posted the other day, I had rarely if ever used the AUTO setting. I think the problem I had is I was expecting it to operate like more cars where you can either set it to blow out hot air, cold air, or something in the middle. What I learned is this system doesn't work like that. It works more like a house heating/AC system where it either blows out hot or cold air to get to the desired temp. It doesn't blow luke warm air. Now that I figured that out and have started using the auto setting, it's a little better. It's getting colder outside so when I set a temp and turn it auto, it will start to blow hot air out of the defrost vents and the floor vents. Once the temp is reached, it blows cool air out of the dashboard vents and it might blow some warm air out of the floor on and off. I guess the thing I don't like is if it's 30 degress outside, I don't want any cold air blowing on me for any reason. I shut the vents which makes it a little better but I wish it would reach the temp, cut off the heat, and then cut it back on to try to maintain that temp. Regardless, I am MUCH more happy with it now than I was 3 days ago.