The fuses are coded as follows.
Fuse/Relay
Location
Fuse Amp
Rating
Protected Circuits
1
30A
Not used (spare)
2
15A
Not used (spare)
3
15A
Family entertainment system (FES)
4
30A
Not used (spare)
5
10A
Keypad illumination, Brake-shift
interlock (BSI), SPBJB
6
20A
Turn signals
7
10A
Left headlamp (Low beam)
8
10A
Right headlamp (Low beam)
9
15A
Interior lighting, Lighted running
boards
10
15A
Cargo lamp, Puddle lamp, Switch
backlight
Roadside Emergencies
308
2010 F-250/350/450/550
(f23)
Owners Guide, 2nd Printing
USA
(fus)