Ford 2010 F-150 - The high-current fuses are coded as follows:

If the battery has been disconnected and reconnected, refer to the
Battery section of the Maintenance and Specifications chapter.
The high-current fuses are coded as follows:
Fuse/Relay
Location
Fuse Amp
Rating
Protected Circuits
1 — Powertrain control module (PCM)
power relay
2 — Starter relay
3 — Blower motor relay
4 — Heated backlite relay
5 — Electric fan relay (high speed)
6 — Trailer tow park lamp relay
7 — Upfitter 1 relay
8 — Fuel pump
9 — Trailer tow battery charger
10 — Upfitter 2 relay
11 30A** Power running board motors
12 40A** Electric fan
13 30A** Starter relay
14 30A** Passenger power seats
Roadside Emergencies
321
2010 F-150 (f12)
Owners Guide, 1st Printing
USA (fus)