AC & RECIRC buttons coming on by themselves?

[JimsSpeed3]

I know this is going to sound strange but my 07 3 is having brain farts or it's haunted. This has happened more than once so I know I can't be bumping them by mistake. I drive the car, no AC & RECIRC is off. I get out of the car to go to work, store or whatever. I get back in the car to drive again and I notice the vent air getting cold. I look down and see the AC is on, and I didn't turn it on and I wasn't using it when I got out of the car. Today, it was the RECIRC button that was on and I never use the RECIRC mode. I've checked the clearance of my hand on the shift lever to the buttons and there's no way I'm bumping them that much. I thought that was the case the first few times but now, no way! Any ideas?
Jim

 

[tsunami]

its posessed??? the ac i could try and explain by saying that if you have it on certian zones it will automaticaly turn on but the recirc i have no idea so ummm yeah anybody else?

 

[Abaddon]

If you are using the AUTO climate mode.. then the system turns on whatever it wants to, whenever it wants to.

 

[JimsSpeed3]

Thats' the thing, I don't have the auto climate control, manual controls. Tonight the AC button did it again and I'm really paying attention to make sure I don't touch the AC and RECIRC buttons. I drive home from work and nothing's on. Take my son to his baseball game, and nothing's on. Drive to the resturant after the game and nothing's on. The drive home from the resturant I decided to turn the fan on, I do and the AC button lights up? WTF? I've had the fan speed on and off all day but nothing esle. Tonight I turn it on again and this time the AC comes on with it. I have no idea, add it to the punch list.
Jim

 

[Abaddon]

Since I don't have the manual controls, I'm not sure of your specific layout... possibly the system doesn't feel that it can obtain the temperature that you want, without the A/C on... is this possible? ie, are you wanting 74 degrees with 95 degree outside air?

Edit:
Another possibility is the humidity level. Potentially the car feels that the outside air humidity level is too high to move to the cabin space without prior conditioning of the air...

 

[ALIEN3T]

you might not have auto climate control. ut if you hit the on button, and have atemputere to gp tp on the settign or the screen it will try still!
to be honest, if you ever turn that button and have a number set its going to try. i dotn see how you dont have auto climate control. if the on is set at any time it will stay that way whenever you get int eh car unless you hit off.? my thought!

 

[Sublime1996]

im noticing this has happened to me too. i dont know about the Recirc button because i always have that on but the AC button does turn on automatically. just this morning, i was going to work and turned the heater on. a little ways down the road, i happen to look down and the AC button was turned on too

 

[Abaddon]

I think I've figured it out... or atelast have a pretty good explanation.

Sublime's post tipped me off when he said that he had the heater on, and the AC light was on.

The A/C serves ONE function in a car. It is a dehumidifier. That is its main purpose. It dehumidifies the air by transferring heat from the incoming air charge until it moves below its saturation temperature, drawing moisture from the air.

In the summer it then passes this conditioned air to the passenger cabin at a much lower temperature then ambient air. In the winter (or when you have the heater on), it first dehumidifies the air, and then heats it to the required temperature. This is done so that you don't get fog on your windshield. Sounds like a backwards process, but remember that the heat comes from your engines coolant, so its really "free" heat. But you do pay the cost of running the A/C compressor.

I think the climate control system is just automatically turning on the AC as it SHOULD, but in this car it is turning on the light as well, making us notice it.

 

[Matthew1785]

I think I've figured it out... or atelast have a pretty good explanation.

Sublime's post tipped me off when he said that he had the heater on, and the AC light was on.

The A/C serves ONE function in a car. It is a dehumidifier. That is its main purpose. It dehumidifies the air by transferring heat from the incoming air charge until it moves below its saturation temperature, drawing moisture from the air.

In the summer it then passes this conditioned air to the passenger cabin at a much lower temperature then ambient air. In the winter (or when you have the heater on), it first dehumidifies the air, and then heats it to the required temperature. This is done so that you don't get fog on your windshield. Sounds like a backwards process, but remember that the heat comes from your engines coolant, so its really "free" heat. But you do pay the cost of running the A/C compressor.

I think the climate control system is just automatically turning on the AC as it SHOULD, but in this car it is turning on the light as well, making us notice it.

i was just going to say that... if your HVAC controls are set to the Dehumidifer setting and you turn the fan on depending on the temp in your car it will either get hot or cold... cold because it's summer

 

[JimsSpeed3]

I think I've figured it out... or atelast have a pretty good explanation.

Sublime's post tipped me off when he said that he had the heater on, and the AC light was on.

The A/C serves ONE function in a car. It is a dehumidifier. That is its main purpose. It dehumidifies the air by transferring heat from the incoming air charge until it moves below its saturation temperature, drawing moisture from the air.

In the summer it then passes this conditioned air to the passenger cabin at a much lower temperature then ambient air. In the winter (or when you have the heater on), it first dehumidifies the air, and then heats it to the required temperature. This is done so that you don't get fog on your windshield. Sounds like a backwards process, but remember that the heat comes from your engines coolant, so its really "free" heat. But you do pay the cost of running the A/C compressor.

I think the climate control system is just automatically turning on the AC as it SHOULD, but in this car it is turning on the light as well, making us notice it.

Sounds like a valid reason and I understand AC systems, I do HVAC/Refrigeration as part of my various duties for my job. It still baffles me though on a totally manual system like I have in my 3 that it would do this. I could see it in the automatic system, sensors would have the AC or heat coming on depending on set points, like automatic HVAC systems in a building. I've never had an automatic system in any of my trucks or cars and the 3 is the first one ever to do this. Also, why would the RECIRC button being going on by itself?
Jim

 

[JimsSpeed3]

if your HVAC controls are set to the Dehumidifer setting and you turn the fan on depending on the temp in your car it will either get hot or cold... cold because it's summer

In a manual system, what is the "dehumidfier" setting? I've never used the defroster. Since I've owen my 3, about a month now, I haven't moved the vent selector off of the top vents. I've had the fan on 0-3 in speed and I have moved the temp control off of cold about four clicks to get a little warmer air in the morning. I've turned it back to cold when the cabin warmed up. I also use to have the temp control over as far as it would go, on the blue line. Now I've got it one click warmer on the notch next to the blue line to see if that has anything to do with it. Still baffles me!
Jim

 

[Matrix03]

My A/C is blowing hot air. whats wrong with it. HELP !!!!!!!!!!!!

 

[Abaddon]

sounds like its out of refrigerant. Did the A/C ever work from the factory? or did it just stop working recently?

Either way.. take it to your dealer.

 

[destrux]

Yeah, when you switch to defrost on alot of newer cars the AC comes on by default, but I've never heard of it doing it otherwise. My MS3 is doing some weird stuff with the fan speed. When I have it set to manual control and I turn the temp knob to cold really fast the fan turns up a few notches and stays there till I turn it down. Doesnt do it if I turn the knob slowly, or if I turn it hotter. It doesnt even do it every time, just every couple of times. Usually I do it as soon as I get in, cause my girlfriend drives with the temp set to 75 and I like it at 65. Other than that, no problems.