K 3500 Truck 4WD V8-454 7.4L (1994)
Oil Pressure Switch (For Fuel Pump): Description and Operation
Purpose:
As a back-up system to the fuel pump relay, the fuel pump is also turned ON by the oil pressure switch.
Operation:
When the engine oil pressure reaches about 28 kPa (4 psi), through cranking the oil pressure switch will close to complete the circuit to the fuel
pump.
