Heat/AC - Mind of Its Own

[Nytimes770]

Has anyone else experienced this - heat or ac is on with air circulation off while driving. And then it'll turn air circulation on itself and it feels like the power/speed setting was increased a notch or two. This happens pretty much on every road trip.

 

[aggiegrad05]

Has anyone else experienced this - heat or ac is on with air circulation off while driving. And then it'll turn air circulation on itself and it feels like the power/speed setting was increased a notch or two. This happens pretty much on every road trip.

The system does its own thing re recirculation...but it's designed that way:

 

[99WhiteC5Coupe]

Has anyone else experienced this - heat or ac is on with air circulation off while driving. And then it'll turn air circulation on itself and it feels like the power/speed setting was increased a notch or two. This happens pretty much on every road trip.

Have you thoroughly read your vehicle owner’s manual, especially the section on the HVAC system?

You may want to post the year, make, model and type of HVAC system for your vehicle.

Some HVAC systems have a humidity sensor, which can alter the user settings on the system, when it senses certain conditions.