Just looking to sanity check something if I could. So according to the manual when setting the climate control to 'Auto':

Quote

The system adjusts fan speed, air distribution, air conditioning operation, and outside or recirculated air to heat or cool the vehicle to maintain the desired temperature.

So the air con should come on and off, is that right? I only ask because when in Auto my air con light stays on all the time, irrespective of whether the internal temperature is higher, lower or the same as outside. If I turn air con off manually the auto setting stays on. Is this expected behaviour? I'd assumed that the air con light would come on and off as the air con turned on/off to maintain the set temperature. Or does it just stay on all the time in auto irrespective of whether the car is being warmed or cooled?

If it *is* expected behaviour then if I manually turn the air con off should that not also turn off auto?

Would be good to know what the expected behaviour is as not sure if mine is working correctly or not. Thanks in advance.

The ac light just means the climate system CAN turn it on and off as needed.

Even if you went to manual max a/c it will cycle the compressor on and off, it does run all the time, only when needed to reach the desired temp/humidity.

11 minutes ago, alexp999 said:

The ac light just means the climate system CAN turn it on and off as needed.

Even if you went to manual max a/c it will cycle the compressor on and off, it does run all the time, only when needed to reach the desired temp/humidity.

OK great, thanks for confirming. So working as intended then? That's good to know.

In which case I find it a bit odd that manually turning off the A/C doesn't deactivate 'Auto' as it's presumably impossible for auto to work correctly with the A/C switch off? (assuming it needs to cool the air of course). I think I assumed that if auto was on and I turned the a/c off but the temperature was set to something v low that the auto would effectively turn the a/c button back on (unless I turned auto off). Seems a confusing system…

So in my scenario above (Auto illuminated, A/C not illuminated) auto will continue to do its job and maintain temperature but only when the set temperature is the same as the outside temperature or higher - correct?

Yeah the system will just try and mix as best it can with AC off. At certain times of yr, you'll find it can still work, but if you've set a temp below ambient it will just be fighting a losing battle.

1 minute ago, alexp999 said:

Yeah the system will just try and mix as best it can with AC off. At certain times of yr, you'll find it can still work, but if you've set a temp below ambient it will just be fighting a losing battle.

Great, thanks for confirming. 

Mines set at 18.5 on auto never alter it, on all the time.

On 7/1/2019 at 2:23 PM, alexp999 said:

The ac light just means the climate system CAN turn it on and off as needed.

Even if you went to manual max a/c it will cycle the compressor on and off, it does run all the time, only when needed to reach the desired temp/humidity.

Alex I’ve been on auto 2 for months! This morning was very cold up here, I noticed when getting in the car ,using remote start as usual, that the A/C light was out. Is this a reaction to the cold weather ? (-3C) . And should I be letting it do it’s thing or put the A/C on myself? I realise the light on doesn’t necessarily mean it’s on. 

8 minutes ago, Alex.S said:

Alex I’ve been on auto 2 for months! This morning was very cold up here, I noticed when getting in the car ,using remote start as usual, that the A/C light was out. Is this a reaction to the cold weather ? (-3C) . And should I be letting it do it’s thing or put the A/C on myself? I realise the light on doesn’t necessarily mean it’s on. 

Not sure what happens with remote start but the A/C will not work anyway if the outside temperature is below +4C anyway despite what the light says.

I know that with this car and other company cars I have driven if you direct all the air to the Windscreen then the A/C light will go off if the outside temperature is low enough as well. Might be the same with the Max Defrost setting, I have never felt the need to use that one. 

My guess is that because it was so cold, the A/C directed most of the air to the windscreen and and did the same as the above automatically. If you did not touch anything the A/C light might have came back on later once the car was fully warm inside. 

20 minutes ago, Tizer said:

Not sure what happens with remote start but the A/C will not work anyway if the outside temperature is below +4C anyway despite what the light says.

I know that with this car and other company cars I have driven if you direct all the air to the Windscreen then the A/C light will go off if the outside temperature is low enough as well. Might be the same with the Max Defrost setting, I have never felt the need to use that one. 

My guess is that because it was so cold, the A/C directed most of the air to the windscreen and and did the same as the above automatically. If you did not touch anything the A/C light might have came back on later once the car was fully warm inside. 

I’ll test that out next time , see if it comes back on itself. The max button I’ve not had the need yet..creates a weather system within the car, I think it’s one of the few physical buttons in the mk4.5.