I've been posting on this site since it was MCO (aug of 02) and I've never seen any posts about this , so here goes:

How the heck is the auto A/C aka climate control SUPPOSED to work. I freely admit that I have NEVER understood the workings of my heater/air conditioning system since owning this car:
-when you hit "Auto" ,2 lights light up: "auto" and "a/c" even when it's 20 below zero outside.........what would I want a/c for in this instance????
-when you hit defogger for the windshield , it comes on full tilt boogie whether you want it to or not, and if you try to modify the fan speed, the function shuts off altogether.What happens if I just want a little defogging????
-I have adapted to the various gremlins living in my heating system by pushing the lowest right option which directs flow to my feet, setting the fan to the first bar, and adjuting the temperatre manually up or down as necessary..........is this automatic???I don't think so. Anyone shed any light on how this system is SUPPOSED to work for me. I am not usually so innept at figuring stuff like this out, but this one has me stumped.June 02 MCS.

 

Well here is my shot- No matter what the temperture Auto turns on the compressor its self (the green light next to the snow flake). This is to keep humidity out. Its not always on though.
Defrost comes on full blast because it was programmed that way, and works best at full tilt.
The last part is a new one to me. Gremilins huh? Sounds like broke to me....

 

On the '05 and '06, you can select defrost by pushing in the button on the right labelled with an up arrow. You can then turn on the AC (the snowflake button) to demist. The fan speed is then under your control. The auto defrost is way too loud for my taste. Like you, I never figured out how to manually work it until I read something on NAM about it.

 

—hold the defogger down for a few seconds and it'll slow down.

—when you hit auto and don't want the A/C hit the A/C button and it'll just turn off the compressor while still blowing air.

I'm somewhat confused about your last question.

Auto is only on when you select it. the rest is manual and will blow at the desired temp. When you start messing w/ fan speed the auto turns off. Here is a tid bit for you, if you want forward and foot air hold both buttons till they both come on.

 

Mine is also a June 02 build. The compressor comes on to reduce humidity as Carpe Diem said. I usually manually select the fan and select where I want the air to come from and if you press and hold the defrost for a few seconds it comes on at the current fan setting, not full blast. Since I don't run it on auto very often I don't remember if the press-and-hold has the same effect in auto. I'll try it when I go home this afternoon. If you like to set it for low fan and "air on feet" try pressing and holding the defrost button until the light comes on, it should stay at the low fan setting giving you air both up and down.

 

Anybody else notice that when they turn on the front Defrost (at "full boogie" setting), or the rear defrost, that they get a lot of static on the radio? I have the H/K in an '05 MCS, and even when I have a station coming in strong, the static almost drowns out the ausdio until I turn down the fan speed, or turn off rear defroster.

 

I haven't had many problems with it at all... I usually run it in manual mode anyway. I figured I would only use the Auto AC when it gets super hot outside or when I'm going on long trips - both of which haven't happened since I've owned my car.

Did anyone notice that the 'display' of the Auto AC where the temp is lit up kind of flickers sometimes? It's weird...

 

No flickering display and no static here.

I just picked up my '06 MCS and I think I liked the manual controls better in my '05. It's nice having it control the temp for you, but it really pîsses me off that I can't have air blowing at my feet *and* the windshield at the same time. I'll have to try holding the defrost button down to reduce the speed. Full tilt boogie is annoying; I don't need it blowing hard all the time. If the windshield starts to fog up a little, why can't I direct *some* air up there and also at my feet, at a reduced velocity?

 

You should be able to do that. Just put it in "semi-manual" mode. Change the fan speed to the desired setting and select both the foot well and windshield outputs. The system will direct air to both locations at the fan speed you desire. It's still automatic in that it will keep the temperature to whatever you have selected. This is prefect for me as I'm not always adjusting the heat, but I can have the air go where I want it to and at my preferred speed.

 

"full boogie" HA!! LMAO i'm going to start using that...

 

You're right. I don't know why that didn't connect in my mind. I guess I'm so used to seeing the windshield icon that I didn't really think about where those arrows were pointing. So the defrost button (on the other side of the Auto button) is just a shortcut for cranking the fan up to full tilt boogie and turning on the rear defroster. Hm, guess they had a blank spot to fill...

The other thing that irks me is when *none* of the "zone" buttons (windshield, vents, foot-well) are lit up. I think you can do this by hitting the full-tilt-boogie button and then hitting the fan-down button once. You end up with the temp displaying, but no fan speed indication and no zone LEDs lit.

 

Hmm, my '06 doesn't do that. If I hit the "full tilt boogie" button (LMAO), and then hit the fan down butting, I get both the fan speed and the tempature displaying.

I was wondering about how to slow down the defogger though; it's majorly annoying. I'll have to try holding the button down.

Overall though, I really like the auto climate. I just set it to 68 when it's warm out or 72-74 when it's cold and let it do it's thing.

 

I'll just throw in a 'me too' here.
This has been discussed before, but in the depths of the "If you like auto-ac you're a seal bashing commie/If YOU like manual you're a troglodyte" threads.
A/C - for cooling AND demisting (I always turn mine off, too)
Defrost - one push=FTB (TM, holdenontoit), push and hold=non tornado inducing defrost mode
Direction - You can change airflow (hands,feet) while still in AUTO mode, but if you change fan speed, you change to manual mode.

 

That's actually a really nice recap. Thanks!

 

Maybe that's it; the fan speed and temp showing, but the distribution buttons are all dark at that point.

There doesn't seem to be a mention of the partial-tilt boogie setting in the manual:
Now veering off-topic:
Unfortunately, it doesn't appear to do anything for gaseous pollutants from the inside air....

One more feature:

 

FWIW, on the '02-04 the F/C switch is done by holding the 'Auto' button for a few seconds.

 

Good info, thanks to all! Glad I was able to add "full tilt boogie" to a few people's vocabulary.It is generally the way I drive the car.There was a thread several years ago that wanted to know if you drive your car differently with S/O's in the car to which I posted "with the wife, like driving Miss Daisy. Alone, drive it like I stole it"

 

Nope, this doesn't work for me. The FTB-button (as it shall now be known) either enables FTB mode or flips you back to the last mode it was in. Holding the button down just flips you back to the last mode.

Now I can't remember what button sends it into an unknown (or at least un-labelled) state, where none of the zone LEDs are lit, but it *is* repeatable.