B4000 Regular Cab 4WD V6-4.0L OHV (1997)
Inertia Fuel Shutoff Switch: Description and Operation
INERTIA FUEL SHUTOFF SWITCH
IFS is used in conjunction with fuel pump and is used to shut off fuel pump if a collision occurs. Once switch is open, it must be manually reset before
restarting vehicle. It consists of a steel ball held in place by a magnet. When sharp impact occurs, ball breaks loose from magnet, rolls up a conical
ramp and strikes a target plate which opens electrical contacts and shuts off fuel pump.