FORD 2011 F-550 v.4 - Manual (Page 79)

If you are driving during extreme high ambient temperatures and idling
for extended periods of time in gear, it is recommended to run the A/C
in the MAX A/C position, adjust the blower fan speed to the lowest
setting and put the vehicle’s transmission into the P (Park) position to
continue to receive cool air from your A/C system.
For maximum cooling performance (MAX A/C):
• Select MAX A/C.
(Panel) and (panel/floor) modes:
• Move the temperature control to the coolest setting.
• Select A/C and
(recirculated air). Use recirculated air with A/C
to provide colder airflow.
• Set the fan to the highest speed initially, then adjust to maintain
comfort.
To aid in side window defogging/demisting in cold weather:
1. Select (panel/floor).
2. Select A/C.
3. Adjust the temperature control to maintain comfort.
4. Set the fan speed to the highest setting.
5. Direct the outer instrument panel vents towards the side windows.
To increase airflow to the outer instrument panel vents, close the vents
located in the middle of the instrument panel.
Climate Controls
79
2011 F-250/350/450/550 (f23)
Owners Guide, 4th Printing
USA (fus)