I agree I'm getting a little carried away with this but I'm a geeky engineer and when things don't work or make sense it bugs me...especially when I paid over $40k for it! It's the only thing I can find to complain about ....besides the rattle in my door panel.

 

Maybe you took me too literally. While my home system (Honeywell) does select weather it needs a/c or heat as needed, yes it has a range of preset temps (and times) that can be as narrow or as wide as you want.

The Ford climate control uses A/C or Heat and blower speed to maintain a specific temp. The Auto feature detects where the air should go. If wanted, you can select defrost and still have the climate control maintain the desired temp.

 

My 2004 with EATC almost always had the A/C going, no matter how cold it was outside. Virtaully never did it have the A/C button unlit. No idea why it always had the A/C on even when it was frigid winter outside, but it did.

Haven't had my 2009 long anough to notice a trend yet, but did notice one day the A/C button was off and the next day the A/C button was lit.

 

All he more reason why I like having simple control and a definite indicator of what is taking place on my 3 ***** (manual AC). Kind of funny but to me I see auto AC as a hassle and am glad I do not have it. I wish you guys the best of luck getting everything the way you want on those sweet new trucks.

 

Well i will try mine out this morning and see how it runs. But im almost certain that AC always runs even when the light is off. Reason being is as soon as you turn it on after driveing for 20 mins it comes out cold instantly.

 

How does the system know which airfow (vent/heat/defrost) you want when you don't want the auto mode?

Here's a lesson on most vehicle climate control systems for the last 10-15 years. The a/c compressor is cycled turns on and off periodically) in every mode except vent and heat (floor). So, defrost, floor/defrost combo, vent/floor combo and defrost only run the compressor. It does not matter what the temperature setting it or what the ambient outside air temp is. The a/c compressor is useful for removing water/humidity from the air, which is often helpful in defrost settings in the rain for example. Likewise in temperatures below freezing, humidity from people breathing inside is removed with the a/c compressor so the windows do not frost from the inside.

For vehicles with auto climate control, just because the a/c lamp is on does not mean the compressor is on, just that it may turn on or be cycled based on what the computers think are necessary.

Don't think to hard. That's what the computers are for. Like jac4x4 quoted from the manual, the computer decides it all and controls where the air flows, how much to move, and if the ac compressor should be on. If you don't want it to control any of that, don't use auto mode and pick it yourself. Well, except you still cannot disable a/c in the modes I listed above.

 

In the cars I have had with auto climate, there has always been a button to turn off the AC. It would still be full auto, but wouldn't use the AC.

 

I have a friend who's an engineer, and he doesn't seem to be able to think normally either.

 

They (engineers) think correctly.

 

Us engineers are always right.

 

If you dont want to use auto turn it off or select were you want it to blow , ie feet , defrost. That is why there is a off button. If you dont want to use it choose a manual feature. Not sure what you are wanting it to do.

 

I'm so happy I found and fixed my door panel rattle I don't care what the auto climate control does!!!

 

What was it, jac? How'd you go about fixing it?

 

I have a quick question. Is it still hijacking if you do it to your own thread?

(Or is it hi-jac-ing)

 

I ran my 07 in Auto, and run my 09 in Auto. What I have noticed is, there is a certain outside temp that determines whether the AC button lights up or not. Not sure what the temp cutoff is, but I would guesstimate that when the outside temp is above 60, the AC light will always come on. When it is below 60, it does not come on. I have never had it light up when it was below approx. that temperature. I usually just turn the AC back off if I don't want it on.