Originally Posted by Atlee
How did you accomplish this? What buttons and levers were pushed/pulled/flipped?
It's not obvious from the Ford E350/E450 dash heating and air conditioning controls - that's why it took me a long time to discover by pure luck how to do it.
My dash has three rotating knobs - one for setting the temperature of the air (that controls both the air heating needed or air cooling needed), one for routing of where the air comes out in the cab, and one for setting the fan speed.
I finally discovered that setting the knob for air routing to it's "MIX" position routes the air only, and at the same time, out of - the long horizontal outlets along the bottom of the windshield and out of the outlets aimed down at the floor for the driver and passenger. There is no longer any air coming out of the dash outlets mid-height that blow out right at chest height.
In hot weather to keep both the upper cab and cab floor areas cool I set the fan speed at 3 or 4, set the routing knob to MIX, and turn the temperature knob well into the air conditioning zone (blue color on my cab's knob).
It takes the fan speed set at 3 or 4, and 3-5 minutes to notice it ... but soon the whole cab area (including your feet and lower legs) will start to fill like they're being bathed in comfortably cool air ... with no cold air blasting directly on your body anywhere. We don't like the chest high A/C outlets blasting directly on us, anyway.
You can modulate the overall cool feeling using the fan speed control and temperature knob - and it works like a champ in hot weather. The Ford cab air conditioning is very powerful, and in our 24 foot Class C it can eventually get and keep the entire coach interior cool - and by using the method I describe we don't get blasted with cold air in the cab in order to keep the whole coach area cool.
It works like a champ.