On Thu, 25 Feb 2016 23:26:00 -0500, wrote:

On Thu, 25 Feb 2016 19:55:48 -0800 (PST), DerbyDad03
wrote:



No, fresh air is standard - and MAX AC does nothing to the fan speed -
or at least it didn't when I worked on Toyotas and doesn't on any of
the cars I currently am aquainted with. ALL Max AC did was put the
system into recirculate mode.

I don't recall which cars it happens/happened in, but hitting the Max
AC button without a doubt increased the fan speed. I've never had a
Toyota, so maybe they do something different.

The fan sound changes because it is sucking air from inside the car
instead of outside the car -

Every GM car I've had MAX is a higher speed on the fan.
Not just sound - fan RPM. It's obvious.