FORD 2010 E-450 v.1 - Manual (Page 226)

Note: With extended use, the flasher may run down your battery.
FUEL PUMP SHUT-OFF SWITCH
(DIESEL-POWERED AND STRIPPED CHASSIS VEHICLES ONLY)
This device stops the electric fuel pump from sending fuel to the engine
when your vehicle has had a substantial jolt.
After an accident, if the engine cranks but does not start, this switch
may have been activated.
On diesel-powered vehicles, this
switch is located in the front
passenger’s footwell, by the kick
panel.
Roadside Emergencies
226
2010 Econoline (eco)
Owners Guide, 1st Printing
USA (fus)