Climate Control Question

[packick]

I have only had my Mustang for a couple of months and am still learning its systems. Here is one I am puzzled about.

When I set the climate control to AUTO and set a specific temperature to keep it at, let's say 70-degrees, it seems to keep the car at 70 degrees as I'm driving along. However, if on a warm day I park the car, run into a store, and then return to the car, the cabin temperature has naturally heated up to way above 70 degrees. Then, when I start the car again, the AUTO light is lit but the air conditioner to cool the car back down to 70 degrees never comes on. I have to manually engage the air conditioner to drop the temperature. Is this normal?

I thought that AUTO meant that 70 degrees would be maintained at all times using whatever control is necessary to do that (e.g., air conditioning, heat, vent, etc.). So shouldn't the air conditioner, in this example, have immediately come on to drop the temperature back down to 70 degrees? Or does this cooling process take a long time to accomplish?

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[Rv-Junke]

I'm having "weird" issues with the new HVAC system in the car. Bringing it back to the dealer again. To me the new system program is not working on many levels...doesn't maintain correct temp, hot when cold, cold when hot, surging variable fan...IMHO, a mess!

 

[Bassfishman]

Mine works as it should

 

[Houn]

I've actually experienced similar symptoms as Op.

Despite maintaining a consistent temp setting, I've noticed differing HVAC behavior on different mornings where the outside temperature was the same. At first I thought it was something related to this being a convertible.

I've since discovered that cycling the HVAC power, OR changing both temp settings (dual-zone mode) restored proper HVAC operation.

I've come to expect this and now have my system set in single-zone mode. If the system isn't operating right, I just toggle the temp down a couple of degrees and then immediately toggle it back. Not really much of an inconvenience.

As for a long-term solution, I'll just wait until Ford, or other forum members, identify the likely cause and remedy. The alternative is missing my car while the dealer treats it like a guinea pig. Not gonna happen...

Rick

 

[batz1917]

Don't know if this makes sense (or just blatantly obvious) but I have noticed that if i want the car to properly cool down, AC NEEDS to be on. It does not automatically turn on when AUTO function is activated. One would think that it would automatically turn on in order to successfully cool a car down but alas. Once AC is turned on it will stay on.

Other than that, on hot days when i turn on the car the system is at full blast to quickly cool down to my temp and once it gets close it will slow down to maintain the temperature.

 

[packick]

Batz1917:

I understand your process, but one would think that if you turned on the Air Conditioner to cool the car down while on Auto setting, even though the fan may slow down as you get close to your set temperature, the temperature could go below your set temperature if the Air Conditioner is never automatically turned off.

Also, with me having to turn on the Air Conditioner, or moving the set temperature up or down to engage the system as Houn suggested, what is the purpose of "Auto?"

 

[drbrian722]

FWIW, If I press the AUTO button the A/C comes on with it most of the time. If I leave it alone the system turns on and off the A/C as needed (light on A/C button also turns on and off). However, if I press AUTO, and then press A/C, to turn the A/C off, it will do what it can and never turns the A/C on. Likewise, if I press the A/C again the A/C turns on, but never automatically turns off. Only pressing AUTO again resets the system. I would also note that the system is pretty quick to act, but I don't assume it to be fully operational until the car is up to temp.
I was told to do a master reset of the MFT system right after I took delivery of the car. I've not had any buggyness with the system, but more than a few folks told me that tip and it may have helped.

 

[packick]

drbrian722:

Is the process for resetting the MFT system in the Owner's Manual? If not, what is the process? Thanks.

 

[opensesame]

I am new to this whole auto climate thing. Most of the time when I turn it on the AC is on and it keeps blowing was past the user set degree. Sometimes it gets too cold and I have to press the AC button. Don't know, but I don't think my auto climate is working properly.

 

[drbrian722]

Part of the problem with vehicle climate control is that they use IR to get a temp reading. That results in cooling until the surface temp of whatever it's looking at is at that temperature. In most cases where I feel that the system has gone a little too far I just toggle the temp up or down two degrees.

The reset is in the Owners Manual (pg. 340), but it's in MFT -> Settings -> System -> Master Reset

 

[Rv-Junke]

Part of the problem with vehicle climate control is that they use IR to get a temp reading. That results in cooling until the surface temp of whatever it's looking at is at that temperature. In most cases where I feel that the system has gone a little too far I just toggle the temp up or down two degrees.

The reset is in the Owners Manual (pg. 340), but it's in MFT -> Settings -> System -> Master Reset

Interesting. Is this confirmed an IR sensor? If so where is it located, and I believe that is a new approach in Ford.

 

[drbrian722]

Not confirmed. The part numbers are YH-1945 and YH-1947 if that helps someone in the know.

 

[Old 5 Oh]

FWIW, If I press the AUTO button the A/C comes on with it most of the time. If I leave it alone the system turns on and off the A/C as needed (light on A/C button also turns on and off). However, if I press AUTO, and then press A/C, to turn the A/C off, it will do what it can and never turns the A/C on. Likewise, if I press the A/C again the A/C turns on, but never automatically turns off. Only pressing AUTO again resets the system.

^^ This. I was going to say the same thing but Brian saved me all that typing.

 

[foghat]

Don't know if this makes sense (or just blatantly obvious) but I have noticed that if i want the car to properly cool down, AC NEEDS to be on. It does not automatically turn on when AUTO function is activated. One would think that it would automatically turn on in order to successfully cool a car down but alas. Once AC is turned on it will stay on.

Other than that, on hot days when i turn on the car the system is at full blast to quickly cool down to my temp and once it gets close it will slow down to maintain the temperature.

My AC automatically turns on and off as needed when Auto is selected. And I too have noticed you need to cycle Auto if you play with the AC button while auto is on.

I am new to this whole auto climate thing. Most of the time when I turn it on the AC is on and it keeps blowing was past the user set degree. Sometimes it gets too cold and I have to press the AC button. Don't know, but I don't think my auto climate is working properly.

Have you tried adjusting the temp as appropriate instead? i.e. if it is too cold and still blowing cold, turn the temp up instead of playing with the ac button and/or fan controls. Also, see above and try turning Auto off and then back on.

 

[Old 5 Oh]

My AC automatically turns on and off as needed when Auto is selected. And I too have noticed you need to cycle Auto if you play with the AC button while auto is on.



Have you tried adjusting the temp as appropriate instead? i.e. if it is too cold and still blowing cold, turn the temp up instead of playing with the ac button and/or fan controls. Also, see above and try turning Auto off and then back on.

Both of these tips are good advice, and necessary. If you TOUCH the AC or fan speed buttons, you are no longer in AUTO mode, even if the AUTO light is still on. You have made a manual choice to turn the AC on or off, or to set the fan speed, and the car will respect that. You have to press AUTO again to get back into AUTO mode.

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