FORD 2013 F-550 v.3 - Manual (Page 101)

Charging System
It will illuminate when the 12–volt battery is not charging
properly. Contact your authorized dealer as soon as possible.
This indicates a problem with the electrical system or a related
component.
Check Fuel Cap
It will illuminate when the fuel cap may not be properly
installed. Continued driving with this light on may cause the
Service engine soon warning indicator to come on.
Cruise Control (if equipped)
It will illuminate when you switch this feature on.
Direction Indicator
Illuminates when the left or right turn signal or the hazard
warning flasher is switched on. If the indicators stay on or flash
faster, check for a burned out bulb.
Door Ajar
Displays when the ignition is on and any door is not completely
closed.
Electronic Locking Differential
Displays when using the electronic locking differential.
Engine Oil
If it illuminates with the engine running or when you are
driving, this indicates a malfunction. Stop your vehicle as soon
as it is safe to do so and switch the engine off. Check the
engine oil level.
Note: Do not resume your journey if it illuminates despite the level
being correct. Have the system checked by your authorized dealer.
Engine Coolant Temperature
Illuminates when the engine coolant temperature is high. Stop
the vehicle as soon as possible, switch off the engine and let
cool.
100 Instrument Cluster
2013 F-250/350/450/550 (f23)
Owners Guide gf, 3rd Printing, December 2012
USA (fus)