Does AC Always Run With Auto Temp Selection?

[JFUSION]

I notice that the a/c activates whenever I choose the auto temp control. Now I understand this if your temp setting is lower than ambient temp, but it does it when I choose a heat setting on cold mornings and my temp is quite a bit higher than ambient. I find myself having to hit the a/c button to turn off the a/c when I am calling for heat. Is there a way to avoid having the A/C come on in auto temp mode if you are wanting heat ?, or am I misinterpreting the a/c light ?. Thanks for any replies.

 

[Woolaroc]

I notice that the a/c activates whenever I choose the auto temp control. Now I understand this if your temp setting is lower than ambient temp, but it does it when I choose a heat setting on cold mornings and my temp is quite a bit higher than ambient. I find myself having to hit the a/c button to turn off the a/c when I am calling for heat. Is there a way to avoid having the A/C come on in auto temp mode if you are wanting heat ?, or am I misinterpreting the a/c light ?. Thanks for any replies.

Great question. I have been wondering this as well.

 

[stripesace]

A/C light implies compressor. Compressor removes humidity.

 

[russell bruesch]

Mine does the same thing with mft 2;11 installed.

 

[JohnnyDop]

A/C light implies compressor. Compressor removes humidity.

Exactly. In many cars the a/c compressor kicks on when ever you hit the Defrost button. The warm dry air will defog alot quicker then moist air from the outside.

Although i do agree its a little odd if its 20F outside and you simply want to warm the cabin. The amount of moisture in 20F air is irrelevant. Using the A/C is just a waste of horsepower and fuel.

Perhaps when the outside air gets below a certain temp it wont use the A/C anymore.

Can any Ex owners that have driven last winter chime in.

Thanks.

 

[JFUSION]

Exactly. In many cars the a/c compressor kicks on when ever you hit the Defrost button. The warm dry air will defog alot quicker then moist air from the outside.

Although i do agree its a little odd if its 20F outside and you simply want to warm the cabin. The amount of moisture in 20F air is irrelevant. Using the A/C is just a waste of horsepower and fuel.

Perhaps when the outside air gets below a certain temp it wont use the A/C anymore.

Can any Ex owners that have driven last winter chime in.

Thanks.

oh I agree when I need defrost mode the a/c running is fine and many times needed, especially in damp conditions.

This morning it was about 10 degrees (celsius), I cranked the heat up to 24 degrees and drove for about 30 minutes and the a/c button was lit up the entire time. I thought maybe it would adjust once it figured out I wanted heat and it was cool out. My concern is that I don't want to waste power and fuel economy if the a/c is going to run when I want heat (not defrost mode). I couldn't verify that the a/c clutch was actually engaging, the other explanation is that the light comes on automatically as part of the auto setting ,but the controller doesn't actually engage the a/c clutch . I'll try to check if I can see or hear the a/c engaging later this morning when I drive it some more. If it is engaging then I'll just get in the habit of hitting the a/c button to turn it off every time. I had automatic temp control on the Fusion and I don't recall it bringing on the a/c light in heat mode. I might have some more information on this later today.

 

[sdm9465]

oh I agree when I need defrost mode the a/c running is fine and many times needed, especially in damp conditions.

This morning it was about 10 degrees (celsius), I cranked the heat up to 24 degrees and drove for about 30 minutes and the a/c button was lit up the entire time. I thought maybe it would adjust once it figured out I wanted heat and it was cool out. My concern is that I don't want to waste power and fuel economy if the a/c is going to run when I want heat (not defrost mode). I couldn't verify that the a/c clutch was actually engaging, the other explanation is that the light comes on automatically as part of the auto setting ,but the controller doesn't actually engage the a/c clutch . I'll try to check if I can see or hear the a/c engaging later this morning when I drive it some more. If it is engaging then I'll just get in the habit of hitting the a/c button to turn it off every time. I had automatic temp control on the Fusion and I don't recall it bringing on the a/c light in heat mode. I might have some more information on this later today.

I've always assumed (and hoped) that the light simply means that the a/c is enabled, meaning that it will switch on automatically when needed. I'd like to know for sure that this is the case.

I expect the light in your Fusion behaved the same way. I know it did in my 2002 Explorer, my wife's 2004 Freestyle and my 2009 Explorer too.

 

[JFUSION]

I've always assumed (and hoped) that the light simply means that the a/c is enabled, meaning that it will switch on automatically when needed. I'd like to know for sure that this is the case.

I expect the light in your Fusion behaved the same way. I know it did in my 2002 Explorer, my wife's 2004 Freestyle and my 2009 Explorer too.

Yeah that could be a possibility, I'll try to monitor it over the next while and see if I can notice the compressor engaging or not. Thanks for the information on this.

 

[JFUSION]

On this morning's trip to work the a\c light eventually turned itself off. It came on upon start up, but somewhere along the trip it shut off. I even tried to turn the system off and restart it and the a/c light would not come back on, so it must have some way of turning itself off when you are primarily using heat. It was a few degrees cooler this morning. It might be turning the a/c on for defrost and demisting , and then turning off later down the road when only heat is needed.

 

[Car 54]

The compressor has a clutch and should cycle on and off depending on demand...just like your house. Some car's (Nissan and BMW for sure) have an A/C OFF Auto setting.

Does pressing a/c button to off remove "auto" or does auto stay lit? I can't remember as my wife generally drive the Ex.

Quick test...ramp your heat up to max and listen for the a/c fans to click on and off. If you can see the compressor pulley...even more confirmation. Lower the auto setting from max heat to max cold and see if you see that there's a point where the compressor clutch kicks on.

 

[JohnnyDop]

On this morning's trip to work the a\c light eventually turned itself off. It came on upon start up, but somewhere along the trip it shut off. I even tried to turn the system off and restart it and the a/c light would not come back on, so it must have some way of turning itself off when you are primarily using heat. It was a few degrees cooler this morning. It might be turning the a/c on for defrost and demisting , and then turning off later down the road when only heat is needed.

It would be nice to know exactly how its working via the manual.

What temp setting did you set it to?

 

[JFUSION]

It would be nice to know exactly how its working via the manual.

What temp setting did you set it to?

I'm running the my temp setting at 22 degrees celsius, temps around our parts in early morning have been 10 degrees celsius and colder overnight. It must have some type of self determining programming to it and it tries to anticipate the conditions needed, which may or may not be totally accurate in any given situation. I'll probably find myself manually kicking out the a/c button when I'm sure that I don't need the a/c activating to reduce unwanted a/c operation.

 

[FordService]

Hey guys!

I did some research on this and found that when the A/C light is illuminated, the A/C will be on unless it’s below freezing outside or if it isn’t needed. This is to keep the humidity down. The A/C light being on just means it’s being requested to be on, not that the A/C is being used.

The following tip can also be found on pages 67/68 of the 2012 Explorer Owner Guide 1st Printing:

“To aid in side window defogging/demisting in cold weather:
1. Select (panel/floor).
2. Select A/C.
3. Adjust the temperature control to maintain comfort.
4. Set the fan speed to the highest setting.
5. Direct the outer instrument panel vents towards the side windows.
To increase airflow to the outer instrument panel vents, close the vents located in the middle of the instrument panel.”

To get a free digital copy of your Owner Guide, you can download one by going to the URL: http://Owner.Ford.com/servlet/ContentServer?pagename=Owner/Page/OwnerGuidePage and selecting your vehicle from the drop down boxes.

Cory

 

[Joe Dirt]

This is also the case in my '07 Camry- the A/C is 'armed' when 'auto' is pushed unless you de-activate it. Same reason- humidity control. If it's needed, it kicks on- same tech.

 

[jrmexplorer]

Mine turned off today too. Has done it in the past. I'd say its pretty normal.

 

[Car 54]

...but we all agree that the A/C light should never actually indicate whether the compressor is on or off, right?

A poster above stated his light went off...that shouldn't happen.

Thanks Cory for the confirmation above.

 

[JFUSION]

Doing some more driving today I hit the auto button selection a couple more times and the a/c did not light up when the auto selection was turned on. It seems to go on and off as it pleases, the controller must have some logic to it and controls the a/c as it sees fit. The a/c light does not stay on all the time, so it can shut down completely at times and come on at other times when in auto mode.

 

[Car 54]

JFUSION- not saying I don't believe you but these would be unlike any other car I've been in. I'd prefer it to tell me whats going on.

 

[JFUSION]

JFUSION- not saying I don't believe you but these would be unlike any other car I've been in. I'd prefer it to tell me whats going on.

Yup, that's the reason why I started the thread, because it is also behaves unlike any other car I've owned. It's not a big deal to me though, I can work with it, I was just curious to understand it. Hope I haven't confused anyone with my observations.

 

[JFUSION]

It seems like the choice to engage the a/c happens more often as the ambient outside temp is closer to the temp that you have chosen for the interior. If I have the heat setting at 22 and it is 10 degrees out the a/c light may not come on or it may turn off after a bit of driving. Today the interior temp was set to 22 degrees and the outside temp was 16 degrees and it would come on, we also can't see what the actual interor vehicle temp is as it can warm up when sitting in the sun and be higher than the outside ambient temp. So it looks like it is influenced by a number of factors and it can turn on and off at will. I think the lamp activation is representative of the a/c actually being used by the system as it sees fit.