Why does the A/C turn on automatically?

[Droid]

It was 56* outside, climate control was set at 66*, "AUTO" was off, A/C was off.

I turned the temperature up to 68. Looked down ten minutes later and the A/C was on.

This has happened a few times before, independent of any input. I'll look down and just notice it's decided to run the A/C. With outside air temp at least 10* below the climate setting.

Has anyone else seen this? Is there any way to make it stop doing it?

Truck in question has the nav and of course auto climate.

 

[JP7]

I use AUTO all the time now, but I do remember the AC coming on at unexpected times before. On some cool mornings I'd set the temp to warm up the truck and it would just blast cold air.
AUTO seems to work alright now, and I haven't seen the problem in 3 or 4 months.

 

[Madcowranch]

I think I heard if you're sitting still, the engine heat can have an affect on the ext. temp. sensor.

 

[SilverBolt]

I think I heard if you're sitting still, the engine heat can have an affect on the ext. temp. sensor.

This is correct. The temp sensor is not shielded from the radiator. When not moving heat from the radiator can cause the sensor to send a false reading making the system think it's hot outside and you need the a/c on.

 

[IRONMAN]

I've also had this happen quit a few times. Hit the auto start and walk in the truck couple minutes later and there the AC on. I normally keep it on Auto as well.

 

[swoop1156]

A/C dehumidifies the air coming from the vents and defroster. AUTO is the best setting.

 

[giffordt]

a/c dehumidifies the air coming from the vents and defroster. Auto is the best setting.

I've heard this as well.

 

[jdowens1]

Dido as to what Swoop stated. when ambient temp is colder outside and auto usually goes to defrost your a/c compressor will run to help dehumidify the air going into the cab.

 

[swoop1156]

Yeah, or else it's like a sprinkler system inside the cab! nah, just kidding, but really -- the windows would get misty/foggy under the right circumstances if it didn't run the A/C.

 

[A10fxr]

my 2011 does that with auto start . in the menu selection on the dash, under remote start allows you to set that up. not sure what the others do.