RAM 3500 Truck 2WD V10-8.0L VIN W (1997)
Oil Pressure Gauge: Description and Operation
SYSTEM OPERATION
The oil pressure gauge gives an indication of the engine oil pressure. The combination oil pressure switch/sending unit contains a flexible
diaphragm and a variable resistor coil. The diaphragm moves in response to changes in the engine oil pressure, which changes the internal
electrical resistance of the sending unit.
The sending unit is installed in a threaded hole that penetrates an oil passage of the engine. High resistance on the gauge side of the sending unit
causes low oil pressure gauge readings. Low resistance on the gauge side of the sending unit causes high oil pressure gauge readings. Sending unit
resistance values are shown in a chart in Specifications.
CIRCUIT OPERATION
The case grounded oil pressure sensor is a variable resistor that connects to circuits G60 and G6. Circuit G60 connects to the oil pressure gauge.
Circuit G6 connects to the oil pressure warning lamp.
Circuit F14 connects to the instrument cluster and supplies battery voltage to oil pressure gauge. The gauge uses two coils. One coil receives fixed
current, circuit G60 connects the other coil to the pressure sensor. As oil pressure changes, the variable resistor in the sensor changes the current
flow through the second coil in the gauge. A change in current flow alters the position of the gauge pointer.
