Ford F-650 2006 Manual page 12

Vehicle Inspection Guide
Engine compartment (with engine stopped)
Any leaks:
HVAC air inlet:
HVAC fresh air filter
(if equipped):
Exercise great caution when working on vehicle equipped with
an automatic fan clutch. The fan starts in motion only after the
engine coolant reaches a predetermined temperature or the refrigerant
pressure (if equipped with air conditioning) reaches a predetermined
setting. The fan will start at this point with no advance warning. Never
reach near, or permit objects to protrude into, the fan blade radius
while the engine is running as this could result in vehicle damage,
personal injury or death.
12
2006 F-650/750 (f67)
Supplement
USA (fus)
Check for signs of fluid puddles, dripping fluid
on the ground under the engine or the
underside of the engine.
Check for debris, leaves, etc. that may have
collected on the HVAC air inlet grille or inside
the exterior module as this may cause reduced
system performance.
Periodically check the HVAC fresh air filter for
cleanliness.